A fellow club member told me he had a unusual brake problem,he had been working on his 34 coupe and needed to put it on his lift and move his Comet off. The Comet has been on the road for about 5 years and has a 351 & a 4 speed transmission. The lift was lowered and he cranked up the comet and put it in gear and the car didn't want to move,he checked to make sure the park brake was off and tried again,he revved up the engine and the car started moving but the drivers side wheel was dragging. He ended up puling the car out of the shop and on to the driveway with his pickup. He jacked the car up and found he adjuster was adjusted so tight nothing would move,so he decided to crack the bleeder and no brake fluid came out,so he thought it might be plugged so he removed it,nothing and everything is dry,there is no indication of a leak. He removed the wheel cylinder and disassembled it and it was as dry and clean as the day it was installed,he ask me had I ever seen anything like that and I told him I had not. It's amazing he has driven that car for that long and he had bled the brakes when he built the car and everything was as you would expect. What could have caused the brake fluid to disappear without leaving a trace of a leak? HRP
Maybe he THOUGHT he had filled the MC and bled it, but actually never got around to it. You know how "old guys" are...........
Like hardening of the arteries, these rubber hoses don't last forever. They can slowly clog and harden causing no fluid to the rear brakes. Easy to check, easy to replace.
When the car hit the road 5 years ago the entire brake system was new,the metal lines,the rubber hoses,the master cylinder,wheel cylinders,the brake shoes and all the brake hardware. HRP
Why it drove well before is a mystery. No fluid to either rear wheel ? Now, what needs to be done - we have several things wrong, so let's start from the top & pull everything hydraulic. If the parts were all new 5 yrs ago, hone with a ball deglazer & wash with alcohol. The quality of the rubber parts you've removed need close inspection, and watch for any parts that were in wrong order, backwards, plugged, etc. Re-assembling the system, pedal linkage & shoes adjusted correctly will give you brakes, as long as no "upgrades" were thrown into the mix.
I would call this a opportunity for improvement. Seems like something was not assembled correctly for the adjusters to work properly. Then I wonder if they rely on pressure from the hydraulic wheel cylinders? Must be blockage somewhere in the line if no fluid in the cylinder, I mean does it bleed properly now? Could be possible it never did get fluid, if he used a glass jar and a tube and bled them by himself. So if it has blockage say some crap in the brass T, that keeps fluid from going to that cylinder. The self adjusters have no pressure on them and are loose, they just keep adjusting them selves til they are tight?
well from what i just read, you said the brake adjuster was so tight.!!! why remove the wheel cyclinders..????? Just curious..!!
Nope, they are mechanical. As the brake lining starts to wear the extra clearance allows for the adjuster to move, one click at a time. When they aren't all corroded up anyway.
If the fluids gone? Start bleeding at the master, crack every fitting to the cylinder to see what happened.
Because the entire system is in question. We don't screw around with brakes leaving things to chance, especially given the quality of parts sold today.
Which wheel had no fluid in the wheel cylinder? If one of the rear, did any fluid leak out of the line when the cylinder was removed? If not, try disconnecting the hard line from the other rear cylinder. Any fluid leak out? If yes, check the tee connector on the rear axle. if no, disconnect the hard line connected to the flex line at the rear axle. Any fluid? If yes, check the tee. If not, progress forward until you reach the master cylinder. In other words work from the affected wheel cylinder back to the master.
When installed and functioning as designed, the self adjusters will only tighten the brakes when the brakes are applied in reverse. The movement of the shoes has to be enough for the adjuster to catch the nest tooth on the wheel, or it doesn't do anything. If there was no fluid in the wheel cylinder, then a properly working self adjuster isn't capable of tightening the shoes regardless of how much clearance exists. I've got no guess as to why the shoes were tight, but if the wheel cylinder was dry then I'd also check to verify that the port from the line connection into the cylinder is drilled thru as it should be. Reading back thru the original post, did the owner verify that it was the adjuster that had the shoes tight and not a stuck cable on the parking brake? Just a while back I had a stuck cable on the brakes on my dually after it had set unused for a while, and it locked that one wheel up dead tight.
Yesterday we spent a couple of hours working on the Comet,the wheel cylinder was cleaned up with a hone and a new wheel cylinder kit was installed along with a new bleeder valve. We bled the brakes and everything worked as it should and a test drive proved the brakes are good to go. We still have no idea how the car was driven that long without brake fluid reaching the drivers side rear wheel but it was drier than a bone or how the adjusters had tightened up enough that the wheel wouldn't turn sitting on the lift when a few weeks earlier he was driving the car. I'm certain there is a explanation but I'm afraid it's a conundrum. HRP
Is the Comet is new enough to have a dual master cylinder there is a priority valve that shuts off fluid to front or rear in case of failure and needs to be reset.
Did you use a factory style combination valve ? The valve will have 2 lines from the master cyl and two out one to the front and one the back and most have a switch for a brake warning light. in the fault position it will shut off the fluid to the end loosing fluid.
Make sure everything is in the correct side, I saw brakes put together on the wrong side once and the adjusters tightened up when brakes were applied going forward, If the wheel cylinder wasn't getting fluid the brakes would adjust as if he shoes were worn Sent from my iPhone using Tapatalk
No,the dual master cylinder has a valve in it. Every thing is plumbed correctly. We checked and double checked the brakes and check to make sure all the lines were free from air,we had a good stream of fluid when we cracked the bleeders on both rear brakes. This was just strange how the line was dry to the drivers rear side and we changed nothing except a stripped bleeder valve & rebuilt the wheel cylinder. HRP
The brakes can only adjust when you step on the pedal and only if there is enough clearance to require adjusting, they can't just keep adjusting until they seize up Sent from my iPhone using The H.A.M.B. mobile app
I probably should have added when everything is working properly, if there was a problem with the adjuster cable and the adjuster turned freely then I could see it happening. Either way, wasn't questioning you Danny, just trying to say brakes shouldn't just keep adjusting because there in a hydraulic issue. I'm curious now what caused that problem, but as we know sometimes things happen that make us scratch our heads. Sent from my iPhone using The H.A.M.B. mobile app
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