- Thread starter iain250
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reidalpine
Enthusiast
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- 1,659
Open bleedvalve to check if there'e pressure in the system -when stepping on the brakepedal Look for gunk or "foreign-stuff" plus air-bubbles-if any bleed system.
Take offending side wheel and brakedrum off to see there's (enough)movement in the wheelcylider-pistons,as in my opinion they are the first thing to cock up when car is sitting still for any lenght of time.They are cheap and easy to locate so if in doubt get a new one
pump all brakefluid through and replace with fresh & waterfree stuff!
If car sits still, remember to pump the pedal once in a while to avoid it getting stuck............... -R.
Take offending side wheel and brakedrum off to see there's (enough)movement in the wheelcylider-pistons,as in my opinion they are the first thing to cock up when car is sitting still for any lenght of time.They are cheap and easy to locate so if in doubt get a new one
pump all brakefluid through and replace with fresh & waterfree stuff!
If car sits still, remember to pump the pedal once in a while to avoid it getting stuck............... -R.
malcolm
& Clementine the Cat
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- Bedford UK
Low brake pressure is an MOT word for brake not effective enough, rather than anything to do with pressure inside the system. There's no real option other than taking off the drums and having a look at the brakes.
Leaky rear wheel cylinders are common. They contaminate the shoe and ultimately make it fall apart. Should be obvious when you pull the hub off.
Leaky rear wheel cylinders are common. They contaminate the shoe and ultimately make it fall apart. Should be obvious when you pull the hub off.
In the old days we always had a problem getting rear brakes to pass the MOT if the tester didn't understand that with no weight on the back of a R4 you don't need much pressure.
After checking they were in good order we would take the car back for test with 2 5gallon barrels in the boot,
After checking they were in good order we would take the car back for test with 2 5gallon barrels in the boot,
malcolm
& Clementine the Cat
- Messages
- 4,527
- Location
- Bedford UK
The MOT seems a bit more forgiving these days. In the past I was failed for all sorts of things, but these days the focus seems to be on if things work and what's going to happen if any non-perfect bit breaks. They have the advise to protect themselves (I consider that a fail that I am allowed to sort without having to bother going back for a re-test).
It's handy to have the 50 minute time for tests. R4s don't take anywhere near that to check, and with the Gordini we used the spare time on the brake machine to set up the rear brake proportioning valve a bit better - new one on that and it was way off adjustment (though not relevant to the earlier question which was difference between rear brakes).
It's handy to have the 50 minute time for tests. R4s don't take anywhere near that to check, and with the Gordini we used the spare time on the brake machine to set up the rear brake proportioning valve a bit better - new one on that and it was way off adjustment (though not relevant to the earlier question which was difference between rear brakes).
thanks lads - stripped her down tonight - yip rear cylinder looked fine but pulled back the dust covers and its a mess luckily the cover has kept it all in one place il get new cylinder and sort out - must say the rear brakes are a credit to her previous owner - looks like he knew what he was doing.