Marshalls 1979 GS (and other shite) brake master cylinder removed and clean up

3,141 · October 6

I suspect one of the pipes to the right of the purple cloth has fractured and the LHM is jetting across.

If it is one of the 3.5mm pipes I have a smallish quantity of pipe and pipe fittings so if it isn't a terrible long pipe I could make you up a replacement if required and post it to you (FOC).

1,758 · October 6

2 hours ago, jonathan_dyane said:

I suspect one of the pipes to the right of the purple cloth has fractured and the LHM is jetting across.

If it is one of the 3.5mm pipes I have a smallish quantity of pipe and pipe fittings so if it isn't a terrible long pipe I could make you up a replacement if required and post it to you (FOC).

Absolute hero mate, thats really kind thank you

1,758 · October 8

Had another quick look this morning and believe I think* I've identified the pipe that's leaking.....

It's the U shaped one illuminated, buried deep and rusted to f#@k. From looking at the diagrams in haynes I'm still not sure what bit it is but it's some kind of junction, possibly that one, possibly not. It's the only high pressure line junction that looks similar.

Looks like someone's already had a go and rounded the nut off or its just rusted away so I'll probably end up having to take the clutch cable out (if that's what's covered with the black box) to improve access. Won't be a quick job anyhow

On a more positive note the front of the car rose up when the system pressurised so would suggest the fault is the line to rear suspension.

She wants to live!

3,141 · October 10

I would suggest cutting the pipe off flush with the fitting and using a socket to remove, if it's rounded hammer on a smaller socket

1,758 · October 10

2 hours ago, jonathan_dyane said:

I would suggest cutting the pipe off flush with the fitting and using a socket to remove, if it's rounded hammer on a smaller socket

Thanks for that sound advice mate, I'll try and do a bit more over the weekend. They're all looking pretty crusty and as the system is only as strong as it's weakest point I'll probably end up renewing a few.

3,141 · October 10

I'll try and remember to check how much pipe I have, probably a couple of meters

6,239 · October 13

What is the pipe size and fitting size pitch? May have a bit too.

1,758 · October 15

On 10/10/2024 at 21:59, jonathan_dyane said:

I'll try and remember to check how much pipe I have, probably a couple of meters

On 13/10/2024 at 09:58, bangernomics said:

What is the pipe size and fitting size pitch? May have a bit too.

Thanks to both of you, I'll definitely shout up should I need anything and grateful for all the help I can get with this one. I'm very lucky to have a guy in basically the next village (Tower Citroen in Retford) who can knock them up for buttons. Access and space is more of the problem currently.

So small update on the GS....

There has thankfully been some progress, the pump gaiter is no longer leaking but I'm still not happy with the big jubilee clips, still not sitting right on the pump. On Thursday I'll be getting the proper "Ligarex" clips on it to hopefully get that issue put to bed. They are 5mm wide and there's actually grooves where they go on the pump for a snug fit.

The leaking pipe deep in the engine bay is proving troublesome to put it politely. Having tried spanners, mole grips etc to try and get at it I ended up taking off the clutch cable shroud to try and improve access.

Total faff and some interesting bolts...

Alas this still didn't allow me to get enough purchase on the offending nut. Well worth trying though and the split pin holding the cable to the pedal was absent so potential disaster avoided.

So last resort was to cut it flush with the nut and get a socket on it. And thats great until you realise theres literally no room to do just that.

After much tea and mince pies, a rare moment of enlightenment arrived and looking at it through the steering column rubber.....bingo. Enough of an angle to allow a socket to be whacked on.....just

How the Lord smiles on us...

At least that's one end out.

Having jacked up the front successfully using railway sleepers and wood offcuts I followed the pipe back towards the arse end expecting to find a join or junction but nothing. One huge pipe front to back heading over the fuel tank.

There is an access hatch that exposes what looks like the rear height corrector

so its one of the four hard lines going into the x4 way connector top left. Jacking up the rear is very interesting, unlike the front has no suspension components exposed.

It's literally a fuel tank in between the rear wheels, x2 areas to protect the rear suspension and boot floor. Despite the sills having been repaired I really dont want to be lifting it using them if possible despite them being the correct jacking points but I can't currently see a workaround so getting under it safely is an issue.

Having discussed a plan forward with folk on here, my mechanic and an MOT station about using a repair section it's an option.

Someone's said absolutely not, others including my mechanic and MOT station have said if installed correctly absolutely yes.

In an ideal world I'd have a ramp, pit and access aplenty, unfortunately it isn't and I don't. With the car fighting me currently, getting it to raise (and then be supported) by itself would help hugely. I know it's not the car, it's just how it is. My citroen guy has recommended it as a solution and has used them on C5s when unable to make up/access pipes. The place selling these is an MOT station themselves, said they have sold hundreds and would have no issue with a repair such as this being presented at MOT. I'm conflicted but think this could be a temporary solution to allow it to be moved and gone through and have the lines made up at a later date. If it fails then I'm left with what I currently have, a GS pissing out high pressure LHM all over the place.

I'll see how things go, get the pump sorted and maybe some of the cars front back together.

3,141 · October 15

You're getting on well!

You should be fine to lift it with a jack under each side of the rear subframe (to L and R of fuel tank) probably using a block of wood as a pad.

3,921 · October 15

4 minutes ago, Marshall2810 said:

Thanks to both of you, I'll definitely shout up should I need anything and grateful for all the help I can get with this one. I'm very lucky to have a guy in basically the next village (Tower Citroen in Retford) who can knock them up for buttons. Access and space is more of the problem currently.

So small update on the GS....

There has thankfully been some progress, the pump gaiter is no longer leaking but I'm still not happy with the big jubilee clips, still not sitting right on the pump. On Thursday I'll be getting the proper "Ligarex" clips on it to hopefully get that issue put to bed. They are 5mm wide and there's actually grooves where they go on the pump for a snug fit.

The leaking pipe deep in the engine bay is proving troublesome to put it politely. Having tried spanners, mole grips etc to try and get at it I ended up taking off the clutch cable shroud to try and improve access.

Total faff and some interesting bolts...

Alas this still didn't allow me to get enough purchase on the offending nut. Well worth trying though and the split pin holding the cable to the pedal was absent so potential disaster avoided.

So last resort was to cut it flush with the nut and get a socket on it. And thats great until you realise theres literally no room to do just that.

After much tea and mince pies, a rare moment of enlightenment arrived and looking at it through the steering column rubber.....bingo. Enough of an angle to allow a socket to be whacked on.....just

How the Lord smiles on us...

At least that's one end out.

Having jacked up the front successfully using railway sleepers and wood offcuts I followed the pipe back towards the arse end expecting to find a join or junction but nothing. One huge pipe front to back heading over the fuel tank.

There is an access hatch that exposes what looks like the rear height corrector

so its one of the four hard lines going into the x4 way connector top left. Jacking up the rear is very interesting, unlike the front has no suspension components exposed.

It's literally a fuel tank in between the rear wheels, x2 areas to protect the rear suspension and boot floor. Despite the sills having been repaired I really dont want to be lifting it using them if possible despite them being the correct jacking points but I can't currently see a workaround so getting under it safely is an issue.

Having discussed a plan forward with folk on here, my local and an MOT station about using a repair section it's an option.

Someone's said absolutely not, others including my mechanic and MOT station have said if installed correctly absolutely yes.

In an ideal world I'd have a ramp, pit and access aplenty, unfortunately it isn't and I don't. With the car fighting me currently, getting it to raise (and then be supported) by itself would help hugely. I know it's not the car, it's just how it is. My citroen guy has recommended it as a solution and has used them on C5s when unable to make up/access pipes. The place selling these is an MOT station themselves, said they have sold hundreds and would have no issue with a repair such as this being presented at MOT. I'm conflicted but think this could be a temporary solution to allow it to be moved and gone through and have the lines made up at a later date. If it fails then I'm left with what I currently have, a GS pissing out high pressure LHM all over the place.

I'll see how things go, get the pump sorted and maybe some of the cars front back together.

I'll hold my hand up as being the guy that said 'no dont do it' 👋

Having said that, if it gets you out the shit, then why not. Id be much happier to use it on a copper or kunifer pipe than a steel one as i expect the olives will bite in better.

I didnt realise or had forgotten the GS had that access panel in the back, Im pretty sure none of my GSA's did. Maybe estates did, i only had one GSA estate.

I try not to look at this thread too much as I just get all wibbly & exciteable over the car 🤣

1,758 · October 15

15 minutes ago, jonathan_dyane said:

You're getting on well!

You should be fine to lift it with a jack under each side of the rear subframe (to L and R of fuel tank) probably using a block of wood as a pad.

Cheers mate, so is that the areas protecting the suspension spheres?

13 minutes ago, Stinkwheel said:

I'll hold my hand up as being the guy that said 'no dont do it' 👋

Having said that, if it gets you out the shit, then why not. Id be much happier to use it on a copper or kunifer pipe than a steel one as i expect the olives will bite in better.

I didnt realise or had forgotten the GS had that access panel in the back, Im pretty sure none of my GSA's did. Maybe estates did, i only had one GSA estate.

I try not to look at this thread too much as I just get all wibbly & exciteable over the car 🤣

Thanks mate I value and appreciate your thoughts. We're all on a journey together and fingers crossed can keep it going

3,141 · October 15

2 hours ago, Marshall2810 said:

Cheers mate, so is that the areas protecting the suspension spheres?

I always tended to go further forward than that, the area under the suspension cylinder rather than the sphere

1,758 · October 19

It's been a hectic week but managed to spend most of today on the car. The pump got some proper ligarex strapping which has tidied it up nicely

Also got the repair joint and some new flared joints made up ready to attempt to get the old girl up and about.

Much time was spent getting it on wooden blocks to get enough space to safely do the repair. Anyway the repair joint fitted nicely and hooked up without issue. New pipe looks grand

After which this happened....

Fired her up and apart from a small puddle of LHM by rear wheel seemed okay. I assume it's a return line for the rear brake as only appeared after i pressed the brake pedal. The pedal itself feels really hard so thats good. Should be able to sort whatever it is when the rear is blocked up.

So engine running, suspension mostly leak free and car back on concrete again. Re attached the clutch cable which allowed access to where the original burst pipe was. The LHM float level was good on highest setting and the warning light on dash went out. I've read that the system is self bleeding but when I open the pressure release nut I only get air out of it no liquid as before, with a high pitch squeal and then the LHM light comes on. When the pressure nut is left closed everything is fine, just an observation as I expected to see liquid and the system air free 🤷

Well happy with that! I still need to bleed the brakes and have a look at the front pads which seem a bit low and could be the reason the handbrake isn't working as well as it should.

Got the fan and shroud back on to get the car running but there was a slight bit of oil on the metal pump protector thingy. The nut is tight but not sure if there should be a rubber O ring between the pump and the hard metal line. There's a bit of a groove which would suggest it may, haynes doesn't say and annoyingly didnt take a photo of it. There's nothing leaking above or around it and the gaiter is nicely leak free. Perhaps @jonathan_dyane/ @Stinkwheel know? I'd rather find out now than after putting the front back together so I'll keep researching.

Could also do with at least a new plate for the front/possibly rear too. Would like to keep it old font with the edges nice and square too to keep it looking good. Any suggestions of old skool plate suppliers that won't take the piss would be welcome, ebay seems a bit hit and miss.

Overall a hugely positive day

3,921 · October 19

38 minutes ago, Marshall2810 said:

It's been a hectic week but managed to spend most of today on the car. The pump got some proper ligarex strapping which has tidied it up nicely

Also got the repair joint and some new flared joints made up ready to attempt to get the old girl up and about.

Much time was spent getting it on wooden blocks to get enough space to safely do the repair. Anyway the repair joint fitted nicely and hooked up without issue. New pipe looks grand

After which this happened....

Fired her up and apart from a small puddle of LHM by rear wheel seemed okay. I assume it's a return line for the rear brake as only appeared after i pressed the brake pedal. The pedal itself feels really hard so thats good. Should be able to sort whatever it is when the rear is blocked up.

So engine running, suspension mostly leak free and car back on concrete again. Re attached the clutch cable which allowed access to where the original burst pipe was. The LHM float level was good on highest setting and the warning light on dash went out. I've read that the system is self bleeding but when I open the pressure release nut I only get air out of it no liquid as before, with a high pitch squeal and then the LHM light comes on. When the pressure nut is left closed everything is fine, just an observation as I expected to see liquid of the system was air free 🤷

Well happy with that! I still need to bleed the brakes and have a look at the front pads which I think could be the reason the handbrake isn't working as well as it should being quite low.

Got the fan and shroud back on to get the car running but there was a slight bit of oil on the metal pump protector thingy. The nut is tight but not sure if there should be a rubber O ring between the pump and the hard metal line. There's a bit of a groove which would suggest it may, haynes doesn't say and annoyingly didnt take a photo of it. There's nothing leaking above or around it and the gaiter is nicely leak free. Perhaps @jonathan_dyane/ @Stinkwheel know? I'd rather find out now than after putting the front back together so I'll keep researching.

Could also do with at least a new plate for the front/possibly rear too. Would like to keep it old font with the edges nice and square too to keep it looking good. Any suggestions of old skool playe suppliers that won't take the piss would be welcome, ebay seems a bit hit and miss.

Overall a hugely positive day

Like a lot, glad it’s worked as planned and been productive, no clue on possible o-ring I’m afraid. And sorry to say the brakes are dead ends, no return lines, so probably a brake high pressure leaking

October 20

Numberplates :- https://www.platesforcars.co.uk/checkout.php?stage=view_cart

3,141 · October 20

A massive step forward, excellent work.

As far as I remember the hard hydraulic pipe out of the pump is the same style as the other pipe seals, a rubber sleeve which can be replaced.

The screw to release pressure/prime the system isn't a bleed screw as such and liquid should never come out of it.

Because the brakes are fully powered not power assisted there is no master cylinder, the brake pedal simply operates a valve. As such the pedal always feels the same even if the system is full of air. Air in the system manifests as a delay between pressing the brake pedal and the brakes operating.

Because it looks like the pipe that either feeds the rear suspension or back brakes (which are fed via the back suspension so that with higher loads there will be more pressure to the brakes) there will be air in the back brakes however unfortunately I agree with @Stinkwheel that if you have a leak on the back when you press the brakes that sounds like a leaking brake pipe as the brake system has no returns.

3,141 · October 20

Also to bleed the brakes you don't pump the pedal you just need the pedal held (or wedged) down and suspension on high, carefully crack open the nipple; air will come out along with lots of high pressure LHM...

1,758 · October 20

Yeah looking at the haynes again of course you're both right, they're dead ends. Do you mean this @jonathan_dyane?

I've never seen one out but assume they sit in the recess of the joint to every LHM pipe and goes in to create a seal? Think i need to whip the pump off again and double check, I suppose it could be damaged or missing altogether. As the original pump gaiter (and also the one I've just fitted) aren't/wasn't leaking, I think this is actually the source of the leak at the front whatever it may be. The angle of the pump would cause it to dribble down to the lowest point so would be easy to misdiagnose as a split gaiter.

3,141 · October 20

That's the one and yes all the pipes have that type of seal, sizes are according to the pipe size (nearly all Citroen hydropneumatic hydraulic pipes are 3.5mm but you can get 4.5mm and 6.35mm, I can't remember if the GS uses either of the two larger sizes) you can usually extract them with a small screwdriver. It won't be missing (otherwise the leak would be massive) so probably damaged or perished.

1,758 · October 20

Thanks mate, looks like the G uses three different sizes but as you say 3.5 is the most common. It's not a torrent but on the basis its not going to get any better if left I'd rather get it right whilst the front's off.

1,758 · October 24

Decided to do a bit more on the G today and now the suspension works lowered herself gracefully onto some wooden blocks. Just enough room to get under and have a gander at this leaky brake pipe.

One end undid alright but the other was a bugger so had to cut it off and I'll get a socket on it when I have more patience/energy.

Old and new here, found the leaky bit pretty easily.

So, went up the road to get my bit of pipe flared and Paul was in between jobs. Next up was a BMW powered 2cv which had just returned from 24hr racing at Spa and naturally meant my 5 minute trip took well over an hour.

All ready for the weekend then....

1,758 · October 27

Started tackling the rear brake pipe which I had to cut previously at 90° elbow joint. I'd describe access as difficult and it took a while to get the nut undone. Finally after literally 3 hours of fucking about it came free.

Elbow removed!

Cleaned up and put new pipe seals in so it was nice. Fitting, of course was the reverse of removal. So one side did up at 1/32th of a turn at a time and the other was marginally easier at the elbow but not much.

Excited at the potentially now leak free car I was looking forward to getting the brakes bled and actually being able to get the car out of the garage. Unfortunately, it was not to be. She fired up, pressurised and.....

yet another leak that was previously alright....brilliant. so think it's 2nd pipe from the left and the one next to it look like it's not far behind. Also on a bend, it's one of the front to back lines.

I've had hundreds of cars over my life and this is by far the hardest one I've worked on. The help and advice on here has been fantastic (as always) and my mate and local specialist has been a huge help. Having spent nearly 60 hours just getting to just this stage I really think it needs someone with far more skill, time and patience to invest. Patch one up, another goes, and so on. Common sense dictates all the pipes are the same age and it's at the stage where someone really needs to make a job of it and do the lot in my opinion. In the words of my mate doing his best captain obvious impression "it's just a few pipes"

........yeah it is

This little girl came and stared at me whilst I was contemplating next steps and that's it decision made, someone else can take over I've done my best with it.

I'll be giving a fellow shitter who expressed an interest early on first dibs just in case they want it but otherwise I'll do a for sale ad here shortly.

1,758 · November 20

Rather than deal with the public again and/or punt this on for f*%k all, I (and it) decided it's going nowhere in the meantime.

In fact it's pissed me off so much I've gone and bought lots more pipe, fittings and seals! Probably when it warms up a bit I'll try and get it up on blocks high enough to get some access. Aim is to redo all 4 front to back lines and possibly/probably the curly brake lines which should eliminate most of the system problems. For £100 it's got to be worth a shot so I'll see how it goes.

3,921 · November 21

21 hours ago, Marshall2810 said:

Rather than deal with the public again and/or punt this on for f*%k all, I (and it) decided it's going nowhere in the meantime.

In fact it's pissed me off so much I've gone and bought lots more pipe, fittings and seals! Probably when it warms up a bit I'll try and get it up on blocks high enough to get some access. Aim is to redo all 4 front to back lines and possibly/probably the curly brake lines which should eliminate most of the system problems. For £100 it's got to be worth a shot so I'll see how it goes.

Have you got the right flaring tool/tools for the 3.5mm and 4.5mm pipe? I know you have a handy Citroen specialist nearby but wondered if the plan is now to do these yourself?

1,758 · November 21

1 hour ago, Stinkwheel said:

Have you got the right flaring tool/tools for the 3.5mm and 4.5mm pipe? I know you have a handy Citroen specialist nearby but wondered if the plan is now to do these yourself?

My mate has the flaring kit already so the deal is I buy all the bits, the 3.5mm tooling and provide tea and cake and we just do it a bit at a time as and when.

Famous last words but there really isn't a lot else wrong with it from what I can see once the systems sealed and brakes recommissioned.

3,921 · November 21

4 minutes ago, Marshall2810 said:

My mate has the flaring kit already so the deal is I buy all the bits, the 3.5mm tooling and provide tea and cake and we just do it a bit at a time as and when.

Famous last words but there really isn't a lot else wrong with it from what I can see once the systems sealed and brakes recommissioned.

Very big like

1,758 · December 1

Managed to do a bit more prep on the shitroen. Access is now much improved with many many sleepers, axel stands despite it not having any, spare wheels for insurance and now able to see what I'm doing.

I had some difficulty getting the clips off the pipes on the underside last time around and was a bit confused. The BX just had a series of plastic retainers that clipped on, easy as but no such luck this time round. These are metal and plastic. After some frustration I manged to snap one off so here it is

I gave Martin at Pleiades a ring, firstly to let him know the pipe had arrived but also to pick his brains about how they were fitted as it wasn't obvious (to me anyway). I asked if they were attached from above as an internal fixing as i couldnt see how they were clipped on. He replied "Citroen have done some daft things in their time but I can't see why the hell they would do that".

Well, yes I can confirm the pipe clamps are indeed fitted from the inside of the car.

So in order to change and remove the pipes you need to remove the seatbelt anchorage points, whip the carpets up and remove the centre console (I've still not managed the centre console)

Absolute genius, cheers citroen. Here's the retaining bolts, long uns too of course

Slow progress but progress all the same. When I've worked out how to remove the centre console I'll have it really worried! Once the last clamp is out each hydropneumatic pipe will be mobile and I can trace them front to back.

That's enough for today anyhow

3,141 · December 1

What a total pill!

Fair play to you for taking this on

1,758 · December 1

Cheers mate. On the basis I can't do too much harm as it's going nowhere it's well worth a go it's just time and patience.

1,758 · Saturday at 15:17

The weather wasn't so bad early this morning so took the opportunity to do some more pipe tracing and shit drawing.

Starting at the rear of the car my mate went underneath and started wobbling each line and I got them labelled up and undone

Access good but this was always going to be the easy end

Working from rear to front we detached all the pipes from the clips leaving only the rubber return lines in place. Snapped this one so I'll get it repaired before it goes back on.

On getting towards the front I knew it was going to be interesting to put it politely. Access confirmed as appalling so discussed options and agreed it was best to try our luck and get the brake master cylinder out to improve things and very glad we did.

The haynes has been utterly useless thus far but gave us a massive clue which turned out to be a revelation. There is apparently an access panel/guard plate behind the drivers front wheel.

With the wheel off, here's a dark shot with arm. Scraping the paint/rust/underseal away we found x2 hidden bolt heads, bingo....

So we can see all the way through now

guard removed

behold the brake master cylinder

This shows the level of pipe crispiness I'm dealing with.

Kin 'ell 🫣

Despite great visibility we just couldn't get the nuts off, even cutting them to get a socket on they weren't shifting.

The last resort was to cut all four pipes and remove the master cylinder altogether. Stating the obvious it's so much easier when it's not on the car

We can use heat/persuasion in a vice to get them free so no drama. My mate has a blowtorch and better vice so he's taken it back to his for the time being, just aswell the weather's taken a turn for the worse.

Will do a bit more when it returns and can start cleaning it up and adding some shiny bits which will be hugely satisfying.

Really pleased with today's progress

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Marshalls 1979 GS (and other shite) brake master cylinder removed and clean up

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