Bleeding Rear Brakes past the compensator

[sclemow]

Has anyone had any problems with the rear brake compensator?

I have spongy brakes after bleeding and suspect that there might be air trapped somewhere in the compensator. Does anyone have any good tips for checking/bleeding systems with them in?

[nick@dunsdale]

old trick remove the rear drums and either wire up the piston's or use an assistant to lever the shoes against the cylinders

Then bleed the brakes, it is a bit of a three handed affair but it works i have used this method many times on mini's on the front and rear brakes.

The compensator is usually first line of thought when there is a spongy pedal, but to be honest that is just the easiest thing to blame i think.

[sclemow]

Thanks Nick,

I'll give it a go and see how I get on.

Simon

[mk1coopers]

Also when you bleed the back up you can get what feels like a good pedal but very little fluid comes out of the rear cylinders, try holding the pressure on the pedal, get someone to slacken the rear bleed nipple (taking all the precautions not to have fluid go everywhere), if not a lot of fluid comes out take your foot off the pedal slightly until you hear a click, then you should be able to get the pedal all the way down (sorry if this was a case of Grandma's / eggs!)

[scooperman]

I found a couple of old bleed screws and drilled them straight through. Then I connected them with enough clear plastic aquarium hose to reach from one wheel to the other, with a T connection in the middle, and a short length of hose from the T to be the output hose.

I jack up the car at both ends because I had problems bleeding the car if it is not level. I replace the rear bleed screws with the drilled ones, connect up the hoses, and drop the output hose into a pop bottle with a little water in it so that the hose end is submerged. Top up the master, and slowly cycle the brake pedal down and up a few times. An assistant can watch the bottle and tell you when the bubbles stop, or you can be a contortionist and hang out of the car door and watch it yourself while you do the pumping. With this method, watching the bubbles in the clear hoses and the bottle, there is no question when the cylinders are fully bled. Remove the drilled bleed screws, reinstall the normal bleed screws.

Key points to remember: car level, move the pedal down and back up slowly, refill the master after a few pumps

[swifty]

Thought i would ad how i bleed brakes > Using a a cheap self bleed system the one that you connect to a spare wheel , i put 45/psi in the spare wheel. Then undo the nipple thats firthest away from the master cylinder working your way to the nearest nipple to the master cylinder. I normally do this twice to make sure all the airs out . Make sure the handbrake is off so that it isnt pushing the rear shoes out when bleeding. In the event that you still have a low or spongy peddle , pump the peddle up with a peice of wood till there is brake pressure on the peddle then wedge the woood against the seat frame or crossmember and leave for 24 hours . Never failed in this method for the 32 years ive been in the car trade . Good luck

[sclemow]

All good ideas, thanks guys, will try some out. I've never had a problem before but never had one early enough to have a compensator.

[Tim]

I have to agree with swifty. I used a Gunson Eezibleed for the first time (actually several times) last week and its much better than I expected. I used it to prime the newly reconditioned master cylinders then work around the wheel cylinders twice. It was very effective. My only criticism is that I used quite a lot of brake fluid, but at least I know all the lines got a good flush.

Tim

[sclemow]

I used to use an eazi bleed and haven't had any problems in the past. I recently got a Sealey set that is pressurised from the compressor and pulls the fluid through from nipples. For some reason I can't get a firm pedal on this one with either set though.