Car failed it's mot yesterday on rear brake imbalance across rear axle..guy said it showed 43% on test...anyone any ideas where to start trying to repair? Thanks in advance 

Taker off drums and inspect shoes/wheel cylinders.

At a guess, you have a wheel cylinder brake fluid leak on one side which has contaminated the friction material of the shoe(s), making that side work badly.

4 minutes ago, Wino said:

Taker off drums and inspect shoes/wheel cylinders.

At a guess, you have a wheel cylinder brake fluid leak on one side which has contaminated the friction material of the shoe(s), making that side work badly.

Is the wheel cylinder easy to replace? Guy who did mot said to check shoes 1st? 

By definition you'll need to replace the shoes because the wheel cylinder has leaked, I'd replace both wheel cylinders and the shoe set simply because the labour is the same.

@sepulchrave is presuming that a wheel cylinder has leaked, without evidence like a low brake fluid level. This could also be a seized adjuster, but checking that means taking the drums off anyway.

You'll soon see, I suggested the most likely scenario in my experience.

I had a seized wheel cylinder piston on mine when I first got the car so check the pistons are free.

@sepulchrave Probably mate, probably. My experience is that the chances of a seized or occasionally stripped adjuster (no parts necessary as a rule, and if they are you won't need shoes or cylinders) or @TMB idea of a seized piston (usually leading shoe for some reason and obviously doesn't always require new shoes) are both non-zero.

I'd think that a seized piston is just a hop, skip and a jump away from being a freed piston/leaking seal?

6 hours ago, rum4mo said:

I'd think that a seized piston is just a hop, skip and a jump away from being a freed piston/leaking seal?

 

Yeah I just whacked a new cylinder on. Can't be too careful with brakes.

Cylinders are so cheap these days that I just replace them both when one fails.

2 minutes ago, sepulchrave said:

Cylinders are so cheap these days that I just replace them both when one fails.

 

Yeah. I remember the old days when we used to buy seal kits and clean it all up and bang new seals on. Was never the best idea really but cylinders were more expensive.

14 minutes ago, TMB said:

 

Yeah. I remember the old days when we used to buy seal kits and clean it all up and bang new seals on. Was never the best idea really but cylinders were more expensive.

 

The BAD old days, I had Hillman Imps and you couldn't get cylinders after the Rootes group went tits up so Girling seal kits were the only option, if the cylinder bore was too worn I'd have to scour scrappies looking for a decent one to rebuild.

My first car was a Hillman Imp. Got if off a neighbour for £70 after he couldn't get it going and decided he just wanted rid of it. Turned out he'd fitted a new set of points and wired them up wrong causing a short. I had a good few years motoring out of it. I remember it had a carbon ring clutch release bearing instead of a ball bearing. Bloody funny cars they were.

Edited 5 April, 20179 yr by TMB

I had about seven of them, some heavily tuned, much faster than minis but terrible handling by comparison.

Yeah, not bad for a fire pump engine. Haha

 

 

Took drums off both sides and no sign of any leaking at all? Just ordered new cylinders and will see if that cures it..shoes are in good condition so hopefully replacing the cylinders will cure it.

 Did you try moving the shoes - screwdriver jammed against backplate lip at 3 o'clock and the try to force the shoes towards the 9 o'clock position by levering, then screwdriver at 9 o'clock to force the shoes the opposite way - as this will check for seized cylinders. The other question would be have you got glazed shoes on 1 side, possibly due to handbrake cable holding shoes against drum - this can sometimes be cured by taking shine off by rubbing with glass paper.

1 hour ago, KeithCheetham said:

 Did you try moving the shoes - screwdriver jammed against backplate lip at 3 o'clock and the try to force the shoes towards the 9 o'clock position by levering, then screwdriver at 9 o'clock to force the shoes the opposite way - as this will check for seized cylinders. The other question would be have you got glazed shoes on 1 side, possibly due to handbrake cable holding shoes against drum - this can sometimes be cured by taking shine off by rubbing with glass paper.

Will try it tomorrow mate cheers 

16 hours ago, TMB said:

Yeah, not bad for a fire pump engine. Haha

 

 

 

Yes, we used to have one, Godiva pump - light weight man transportable fire pump, hum, it felt a bit heavy to me! Always started with one turn of the handle during its monthly checks.

Had a friend at high school who's brother was driving back to Kinloss and found a milk tanker on his side of the road it seems just after a bend near Laggan - completely cremated he was!

Had a guy working for me who's father worked on the assembly line, this guy ran an Imp and the plan was, you didn't need to have any tools - they were "borrowed" from the factory to do jobs at home then thrown in the bin, messy wasteful beggars - or maybe just story tellers!

@rum4mo I used to work with someone who used to work at Linwood; he had no similar tales (and we did swap tales of work and hobbies during quiet times).

2 hours ago, KenONeill said:

@rum4mo I used to work with someone who used to work at Linwood; he had no similar tales (and we did swap tales of work and hobbies during quiet times).

 

I'd like to think that you're version is nearer the truth, but this guy's family lived in Johnstone which was handy for Linwood, but I seem to remember it used to be a place best driven through briskly! I probably embellished that tale a bit, it was just torque tools that were "borrowed" and binned - maybe the risk from sneaking them back in was not worth taking?

 

I have a friend that worked in "bad boys schools" - not his words, just a generic term commonly used, and he knew exactly which places to avoid - from his experiences in reuniting some of these boys with their school!

@rum4mo Aside from my mate may not have mentioned stuff (also AIUI he was bodyshop, not production line) we used to travel through Elderslie and Johnstone at least 2 weekends a month from home to grandparents or uncles without any bother to speak of (but were well aware of the Esso station with the sign "these premises are patrolled by a tiger").

I had several cars made at Linwood, Chrysler Avengers and Sunbeams. Nice to drive but used to disolve before your very eyes. Passed my driving test in a Sunbeam 1.0 LS which had a modified Imp engine. 22 seconds to get to 60 mph (if the wind was behind you)

 

Sorry for the thread derail.

The last version of that engine was the 930 in the Talbot Samba, to be fair they weren't much like the original FPA, much bigger valves, higher compression and hairier cams.

My sport lump made about 80bhp but threw a rod through the side of the engine, I found a big lump of engine block lying on the exhaust system, it let go at about 7500rpm.