Mechanics' know-how

[garethj]

I was reading a thread on Pistonheads last week about a bloke who'd taken a whole day to change his brake pads. I'm sure we've all had jobs like that, but as he explained it most of his mistakes were due to inexperience. Between us here, we must have dealt with more breakdowns than an American psychiatrist so here's a handy thread where we can share mechanics' tips. Add as you like and I'm sure it'll be useful.

Basic safety
Use goggles when working under the car. Try a few to see which ones don't mist up and are comfortable, but getting yourself in position under the car and then having to wriggle out because there's dirt in your eye really slows down your work. Make it a rule to always put them on when you slide under the car.

Have a fire extinguisher or at least some water and a towel to smother flames. Fires rarely happen, but when they do it's quite serious.

I use disposable latex gloves, so when they get covered in slippery goo I can peel them off and put some new ones on. Box of a hundred is cheap.

For the real basic safety stuff, tie back any long hair especially when leaning over a running engine (heap big scalp taker), don't get under a car that's only supported with a jack and disconnect the battery if you're in any doubt about sparks. Never make decisions against safety but if favour of convenience.

Tools
Plusgas is my choice of penetrating spray, others swear by WD40 but Plusgas works for me.

Brake cleaner spray is the ultimate degreaser, paraffin is very good and cheap if you've got a lot to do.

Mole grips are brilliant, and you can use them on a screw where the Phillips head has been destroyed.

For socket sets, you can never have enough extension parts. 3" and 6" are a minimum, any others are a bonus. Long reach sockets are handy for nuts where there's a long bit of bolt thread sticking through. Otherwise a half decent socket set is fine, and you can always buy extra 13mm sockets or whatever, if needed.

I bought a Dremel recently and while I'm far from using it every day, it's quite handy at times. Buy some fibreglass reinforced cutting wheels, the standard ones won't cut the string on a beaded seat cover.

Stubborn fasteners
This is the part that most people struggle on but don't despair, there are lots of methods at your disposal and one of them will work.

1. Spanner, make sure it fits well, use the ring end rather than the open end if you can. You can get double the leverage easily, by hooking the ring of another spanner over the crescent of the spanner you're using. Voilà, twice as long so twice the leverage. Depending on which bit of the crescent you hook it can work for loosening and tightening, and it also works for Allen keys.

2. Hammer. Apply steady force with your hand on the spanner, then bang the hammer too. The shock sometimes helps to jar it free. Those with impact wrenches can look smug here, but I don't have one.

3. Releasing oil. Plenty of it, hammering the head of the bolt to help break the rust join and leave the oil 10+ minutes to work.

When you apply torque with the spanner, try working it in both directions rather than just loosen. You want to break the rust loose, not shear the head off.

4. Spanner or socket rounding the bolt head? Does a slightly smaller imperial socket fit with some tapping? If not, mole grips are your friend. Wind the thread so you can just about clamp them over the bolt head, then pop them open and wind the thread in a bit more. You should just be able to clamp them shut while swearing, that's good and tight on the head.

5. Still not coming off? If you've got time, do some more hammering of the bolt (along its length to get the threads free) and apply more releasing fluid, leaving it overnight if you can. I've heard of soaking a rag in releasing fluid and leaving it over the bolt overnight, go for it if it'll make you feel better.

6. If you're short of time, you need heat. Fag lighter isn't enough, neither is a crème brûlée torch. I've got a mapp gas bottle and nozzle which cost about £15, if you've got an oxy acetylene kit or brazing equipment, go to it. I used to think that getting the nut hotter would expand it, avoiding heat on the bolt. Basically this isn't really needed, get the whole lot up to almost cherry red and the spanner will take it off easily. The thing you want to avoid at all costs, is snapping the head off the bolt.

You snapped the head off the bolt, didn't you?
This is a real swine, but not irretrievable. First get busy with hammering and releasing fluid, treble the dose you tried earlier, at least. The steps available now depends on where the offending bolt is on the car and how much room you've got around it. The steps I've used are:

1. Use a hacksaw or Dremel to cut a slot so you can bang a screwdriver in. Use heat, lots of it.
2. Centre punch and drill down through the bolt. My idea of central and what I actually get are rarely the same. Increase the drill size until you're about to break into the thread, then use heat, lots of it. Run the drill backwards while wiggling it about and this can bring the bolt out.
3. Weld a nut onto what's left of the bolt, then you can put a spanner on it again. Did I mention you should use heat? If the nut snaps off, weld it on again. This is really your last choice without drilling the whole thing out and re-tapping the thread bigger.

When welding a nut onto a broken stud, the usual rules of mig welding apply. Get the end of the stud clean (Dremel) so you can weld to it, and get a good contact on the other end so you can clamp your earth lead to it.

[Cavcraft]

Choke and carb cleaner is excellent degreaser for oily engines.WD40 on a rag and wiped over exterior plastics makes them shiney.Oh, and plus one on the goggles. Pissing about with an old Merc meant a trip to A&E to have rust removed from eye. Not at all nice.

[ashmicro]

+2 on the goggles. As a spectacle wearer, goggles arent alll that convenient/practical, so I use UVEX Astrospec over-spectacle safety glasses.

 

 

And these, are the dog's bits:

 

 

 

 

Nut splitters, used by me frequently to get the nuts off knackered track-rod ends and balljoints. In extreme circs, I will use an air-nibbler.

[garethj]

Electrics

Nothing to be wary of here, but you'll need some basic tools again. Here's what I've found useful over the years

Tools
Soldering iron: I got a gas one from Maplins which is plenty hot enough and of course doesn't need an extension lead.

Multimeter: One that does engine revs, dwell angle etc. They're not expensive these days.

Loads of wire, spade connectors etc from Vehicle Wiring Products. Get plenty of earth wire that's good and thick, 2.5 square mm is handy. Buy new fuses and a spare relay or two while you're at it.

Wire stripper: I got one that's sort of spring loaded and will do any thickness of wire, it also works ok as a crimp tool.

Fibreglass pencil, I got one from Halfords for about £3 and it's brilliant for taking the oxidation off contacts without taking the plating off.

Brass wire brush, one that looks like a toothbrush but for Desperate Dan.

One you'll need to make up a pair of very long (like 4 metres long) thick wires with crocodile clips at one end, and spade connectors at the other end. Put a switch in there, I got a switch that lights up when it's on because I'm such a showoff. This means that when tracing electrical faults, you can put the croc clips on the battery and take 12V straight to the thing you're testing, without taking it out. This is such a useful thing I should patent it and sell the idea to people for a hundred quid, and they'd still thank me. If you're likely to be clumsy, put a fuseholder in there in case you short something out.

Armed with these tools you can tackle almost anything electrical on an old car.

[jonny69]

6-sided sockets. I don't know why this country persevered for years with 12-sided sockets when they just make a mess and round everything off. 6-sided is where it's at, nigga.For broken studs I have had limited success with easy-outs. One came out very easily and the other wasn't going to budge so I withdrew the easy-out in case it snapped. Instead I drilled it out completely and put a helicoil in. Cromwell Tools do very good helicoil kits for not much dollarage. These were cheapo easy-outs though, and I have since upgraded to some Dormer ones which are much better quality.

 

Edit: make that now two successes with easy-outs

[r.welfare]

Six-sided sockets are definitely a good idea.Also, a magnet that operates on a similar principle to an extendable radio aerial is an invaluable tool for retrieving nuts, bolts and screws that fall from your hands into the bowels of the engine bay, or into the door panel.Most modern shite uses plastic clips/screws that "spread" when tightened to fasten a variety of stuff from undertrays and wheelarch liners to door and boot trim. These invariably break (or are missing from work by a previous owner/mechanic), so a cheap selection box from eBay is a good investment. I bought one from the States for about a tenner with multiple Honda fitments (over 200 clips in all), which assists greatly with both my wife's car and my own.

[Vin]

+1 on +Gas :)I would also recommend a breaker bar for stubborn gubbins. Very useful.I also have a set of 'Metrinch' sockets and spanners which are excellent on rounded nuts and bolts.Combination of all three (+Gas, breaker & Metrinch socket) can work wonders

[Station]

I have two of these, a big one and a small one, and they always remove totally rusted solid bolts.



Ratchet spanners are good, I decided to buy a load when it took me 1/2 hour to remove a bolt on an exhaust centre section which was in a cavity.
The only tool Halfords make which are pretty shite, their ratchet spanners don't last long. I got the fixed neck and the swivelly bendy neck ones. Half have mysteriously vanished!

http://washford.scene7.com/is/image/Washford/205070?$prod$

Also got a set of brake pipe spanners, which are six sided and remove bolts quite well. (These have all also been stolen).



I have found digging into a bolt with an angle grinder on the top will always loosen it up, and can be undone by hand.

The only good advice up there on removing bolts is the heat thing. You can get bolt extractors for that, also using stilson grips on them works.

[mouseflakes]

6-sided sockets.

+1

[jonny69]

brake pipe spanners

+1 for this as well. Took me seconds to ruin all my brake bleed nipples and then years to get some brake pipe spanners

[Dead_E23]

I use disposable latex gloves, so when they get covered in slippery goo I can peel them off and put some new ones on. Box of a hundred is cheap

I have treated myself to some rather luxurious 'Mechanix' gloves with faux-suede fingers and palms and a lycra-like back. After using latex gloves for years, they are GR8 because you're not constantly tearing them on everything you touch. Not particularly cheap, but I'm very pleased with them. The only drawback I've found is that they're not oil-proof so you still need to keep some latex ones around for oil changes and so on.My tip for using the 'forked wedge' balljoint splitters that you hammer into the joint: cut a thick 'U' shape out of the side of a bean can and slide it in first so it'll protect the rubber boot as you bash the fork in. It helps the wedge slide in nicely and you don't tear the boot.btw, I marvelled at that thread on PistonHeads too. There are some real experts on that forum.

[Richard]

6-sided sockets.

+1

7-sided sockets?

[CreepingJesus]

Feeler gauges, and a micrometer. I'm rarely without mine, maybe because I love measuring stuff. It's not so long since the last OHV engines shuffled off, so there's still plenty around; and you won't be doing the valve clearances without the feelers.

Circlip pliers. Trying to remove circlips with anything else is just folly. I got a set from Machine Mart, which covers straight, angled, inside and outside; and they've been worth every penny.

Pullers. A basic three-leg mechanical set will do fine, and will budge most stuff on a shaft, or with a bore. As a callow youth, I watched my dad and his mate set about changing the wishbone bushes on our Mk5 'Tina. About 10 minutes in, they looked at each other and wished for a set of pullers...

[seth]

PLusGas is fantastic. I don't know why people insist on persevering with WD40 when it is not a penetrative oil.Various lumps of wood: GR8 for wheel chocks, using between jack or stands and chassis, "soft" levering etc. Proper torque wrench: I suffered for years with one of those really basic bending beam ones inherited from my dad. Finally bought a proper adjustable click, ratchet one last year and its a revelation. Took some time to find one with imperial measurement and a wide useful range of torque though. Ended up with a Halfords pro job..

[scooters]

carb cleaner is great for starting stubborn engines - don't do it too often though - quick skoosh behind the air filter

[dollywobbler]

If when you paint your car, you suffer from the same issue I have, and seem to get more on your hands than the car, simply sneak past the missus and pinch some of her nail varnish remover pads.The paint comes straight off your hands and you smell lovely and fragrant too. Warning - this perfumed aroma may give you away...

[Milford Cubicle]

YO.

Been having running problems with my car, turns out the timing belt was slack and the timing's gone to pot.

 

Can anyone help me find the top dead centre on the engine? It's a '95 Astra TD with an Isuzu engine.

I am aware that there's a wee nick on the crank pulley, but it's been rendered invisible by the rusty and battered appearance of the pulley. There's a little dimple on the outside of the pulley, should this correspond with the TDC mark?

 

 

This image from the enormous set titled Cavalier TD Cam Belt Replacement 2007 suggests not

HALP.

[Minimad5]

Milf - failing that, could you not pop out a Glow Plug and see if the piston is TDC ?If i am wrong - tell me to shut up

[Rocket88]

I'm not sure if this true or not, but there is a tale of "someone" being told to make sure that the mark on the pully lined up with another mark [not sure where] anyway, this "someone" proceeded to take the pulley off, and reposition it to coincide with said mark............if think disaster ensued fairly shortly afterwards

[Richard]

Further on in the set you see the pulley removed, and he appears to have aligned a mark on the end of the crank with a hole in the bottom of the block. I think that might be the way to go. Disaster won't ensue as long as you turn the engine by hand for at least two full revolutions.

 

[Rusty Pelican]

Back to tools , Ive found a 1/4 drive socket set just about THE most invaluable tool EVA , GR8 for difficult to access nuts and the like , Britool do / did a friction drive ratchetless ratchet , these are the best thing you could ever buy , available in all three common sizes but not cheap.

[inconsistant]

Ermergerd useful thread resurrection. I have nothing to add, other than page 424 def isn't the most helpful place for this. Therefore bump.

[derskine]

Will start adding shit then!

 

 

These Irwin bolt grippers are the best thing for rounded bolt heads, they can also remove studs if you don't mind knackering the stud.

They can be used on cap screws (allen bolts) if you've rounded the centre out too - just smack it over the outside.

I've abused mine to hell and back smashing them onto anything that gives me grief and they work exactly the same as the day I got them 3 years ago.

[twosmoke300]

the cheap (£15 ish ) sealey torx/allen/ spline bit kit is great for beating into rounded allen bolts / torxs etc . Cheap enough to be disposable but good enough to do the job . Also can be used to get broken ka spark plugs out too.

[cobblers]

To remove Ka spark plugs easily, fill the well around the plug up with plusgas and run the engine up til it's warm. Ideally, to get the engine warm enough, you should drain all the coolant and oil into a bucket then hold the engine at 4000rpm until it makes grinding noises and stops on it's own accord.

 

Remove the spark plug carefully, replace with new adding a little copper grease, and then pour all the oil/water mixture into the crankcase of the engine. There is no need to manually add any coolant, as this will eventually refill itself through the leaky/snapped off heater valve as rain collects in the scuttle area.

[Luckythirteen]

^Ha...Ka misadventures!

 

Headtorch. Because you cannot ever see too much (unless you're poking the offside rear arch of a Ka with a screwdriver), and there will be shadows.

Magnetise your screwdrivers, and small fastener tools. It's best not lose a tiny fastener down, say, an inlet manifold.

[mrcitroen]

Those Irwin bolt removers are ace. I bought mine to remove a borked torx head caliper bolt on my Xantia. Worked a treat, and have had good use ever since.

[doobietoo]

Simple trick to remove stubborn nuts and screws.... it is often easier to slightly tighten it first to break the seal, This also avoids knackering the bolt or screw head on the loosening side so you still have an undamaged area to grip on when you loosen it.

[brickwall]

Aye, a big Stillson sorts most bolts out.

[Inspector Morose]

Grease your screws! If you're screwing into wood, rub a bit of grease or candle wax on the thread. It goes in a bit easier and when you have to remove it later it'll come back out again. (Only really applicable to old buses and older cars but hey, it works)