No Rear Brakes and Hard Pedal

For those who didn't see my post regarding my engine idle issue (which seems largely resolved thanks to the many good suggestions), I have recently acquired a '69 GS400 vert. It's largely original, with about 71k on the odometer.

The car has had a hard pedal and pulled to the right since I got it. It does stop though. I originally thought it all that was needed was a brake adjustment and a new power booster. I tested the power booster and it seemed fine, so I figured I would pull a drum or two, see what's up and adjust the brakes. Fronts seemed fine, so I went to the rears. After spending some time diagnosing, I found that neither rear drum is operating. Pressing the brake pedal with the car stopped or running doesn't move the shoes at all. Zilch. Nothing. I also had someone apply pressure to the pedal while I opened the bleed valves. Nothing. Not a drop.

It looks to me like the hard line coming from the proportioning valve is all original. I can't tell whether the rubber line at the rear end of the hard line that goes to the distribution block mounted to the axle is original. So, my initial thought is that there is a clog. That said, I don't want to undertake replacing the hard lines and the rubber to the rear, only to find out that it's something else that was easily diagnosed that I missed. Any suggestions for what else I should look for to narrow down the repair? Should I just replace all of the lines at this point, including the fronts? If so, should I also replace the proportioning valve? I'm not looking to turn what could be a relatively simple fix into a major project since I am a weekend mechanic, no lift, etc.

Also, I did look at the hard line that runs from the proportioning valve to the rear axle just to get a feel for what it will take to replace it since I'll be on my back for the job. I see that there is a clip just above the left rear control arm that holds the brake hard line and the two fuel lines in place. the clip appears to be bolted to the top side of the frame, between the frame and the chassis. I gave removal a shot, but I really don't see how that bolt is removed. I presume that it was put there before the chassis was mated to the frame. What have others done? Have you just cut out the brake hard line and routed the replacement around that bolted clip? Can the replacement hard line be installed without having to remove major rear end components. It's like it can be installed, but I don't want to end up getting the part and finding out that I need a lift, have to remove control arms, etc. I'd do it anyway of course, but I'd like to know what I am in for before I dig in. I assume that many of you have tackled this project.

Also, any suggestion as to where to get parts is most appreciated. I see that Year One has some, but I'm not sure they have everything if I need to do a major brake overhaul.

Thanks in advance for any thoughts/suggestions.

 

Replace the rubber line first, slide the drums back on and see if rear brakes will bleed.

 

Alan,
just so we are all on the same page you have four wheel drum on the car, because some of the tests would be different than disc brakes. Correct? We just want to be clear. With any brake system if the car pulls to the left that would mean the right side is not working has hard as the left so the car would pull to the side with the stronger stopping force. When check the side that is not working, open the bleed screw and slowly push down on the brake pedal make sure you have something to collect any fluid that may spill. If you get fluid out close the bleeder and then compare it to the other side. if you have about the same amount of fluid on each side I would replace the wheel cylinder for the opposite side of the pull, one of the cups in the cylinder maybe frozen. The problem in there rear is probably the same frozen wheel cylinders, you may just want to replace them all along with the fluid. The rubber brake lines should be ok because you have the same amount of fluid. I am assuming that all the steering components and suspension are ok.

Ron

 

Seen similar problems may times. I would suspect the wheel cylinders may be seized and/or the rubber break line(s) have deteriorated. The rubber lines can look okay on the outside but still be bad. Also, does the car pull one way when you first leave then pull the other way once you have traveled some distance? If so, you may have the left front drum dragging at first then getting hat and fading resulting in a pull to the right. I forget if the 69 has a single or dual master cylinder, but you may also have a bad master if it is a dual reservoir.
Keep after it, you'll find it.
Robert

 

Thanks Ron. It is 4 wheel power drum. The car pulls to the right, so the first thing I did was look at the front left. That was fine, so I went to the rear left. No brake action there at all, so I looked at the rear right. Nothing there either. There is no fluid coming out of either rear bleed valve under pressure, whether with the engine running or not. If I am correct, this would seem to indicate a clog and not frozen cylinders, right? If the cylinders were frozen I should still get fluid out of the bleed valves I would think. The steering and suspension components are worn and are next on my list of things to fix/replace once I get the brakes working properly. It could be that the pulling is due to no rear brakes and worn front suspension/steering components I presume.

 

Thanks for the encouragement Robert. Dual reservoir system. Car constantly pulls to the right when braking. I'm thinking now that it's worn steering components combined with non-functioning rear brakes. I'll check the rubber line at the rear axle (once I clear off the 45 years of gunk that's accumulated at the point where the hard line meets the rubber line :laugh. That might be the culprit.

 

Seems like a simple fix and worth a try. Certainly replacing the line can only help. Thanks TexasJohn

 

As always, thanks Larry. I looked at the thread yo referenced. It relates to disk/drum configurations. I'm 4 wheel drum, so I assume the thread doesn't apply to my situation. I think rather than disconnect and blow air, I'm going to replace the rear rubber line and the two hard lines that run from that rubber line to each rear wheel. It's the likely suspects from what I have gathered. At any rate, it won't hurt. The lines are all probably 45 years old anyway. If that doesn't fix it I'll start to work my way forward from there. The brakes are a simple system, so it shouldn't be impossible to hunt down the problem.