|
|
Member
Posts: 14
| Rear brakes only, everything is new, properly installed. After much testing both sides stick. Can be broken free but only while on stands, not with weight of car.
Get rolling, put on brakes, hear a loud bang and they are stuck. Both in D & R. Put in N, let sit a bit and they will spin again.
Engage gear, apply brake, same thing. Repeat as long as you like.
Thinking maybe master cylinder. Any other ideas?
Thanks.
|
|
| |
|
Expert 5K+
Posts: 8443
    
Location: Perth Australia | If the brake system is stock, it will be a single circuit system
If the locking is hydraulic, it most likely will be the flexi hose at the rear axle or the line from the distribution block to the flexi.
Get the brake to lock, then undo a bleeder on either rear wheel and see if it has lots of pressure (as if someone has their foot on the pedal), if so, it means the fluid cant return to the MC, if it doesnt, it means its a mechanical fault in the rear brakes (put together wrong or maybe weak return springs ect)
If you have a dual circuit system, could be the same thing, but also proportioning valve, wrong type or faulty MC
Pictures of what you have here might help
|
|
| |
|
Member
Posts: 14
| Much obliged for the help.
It is a single MC and when you open the bleeder there is pressure so I'm thinking you are on the right track with the fluid not being able to return.
The flex hose has been replaced. I will check you thoughts on where the blockage may be.
It has to be hydraulic or they would not spin again after a while and the pressure has let off.
Back under the car. Thanks again. |
|
| |
|
Expert 5K+
Posts: 8443
Location: Perth Australia | Easy to check then
Just follow the rear brake line (with the brake stuck, but no pedal pressure), starting from the distribution block, crack the fittings, there should be no pressure.
Once you strike oil (get pressure, Texas oil joke  ), the blockage or restriction will be between where there was no pressure and where there was pressure
If its in the steel line, make or get another one, as it will be rust, which is a brake line waiting to burst and ruin your day in many ways
|
|
| |
|
Member
Posts: 14
| Great idea. Thanks so much.
The conventional wisdom says the proportioning valve is bad but I agree with you, first the line should be checked from the rear flex hose (new) to the valve block (old).
Those valves can fail but from what I am hearing its a rare event. Much more likely the line has issues between the valve and the rear flex line.
That will be Saturday's project.
This is addition by subtraction. Find out what is working and then discover what is not.
Its frustrating and aggravating, but its 55 years old and comes with the territory.
Thanks again.
And I got the joke w/o the explanation!
|
|
| |
|
Expert 5K+
Posts: 8443
Location: Perth Australia | There shouldnt be a proportioning valve in it unless you have fitted disc brakes to it
|
|
| |
|
Member
Posts: 14
| So that block at the front of the car (one line in from MC, one out to the rear, two out, one to each front brake) is not a valve?
Just a block?
That is not what I have been told but I am not knowledgeable.
Seems you are.
Thanks for the info.
|
|
| |
|
Expert 5K+
Posts: 8443
Location: Perth Australia | Its just a distribution block
See how you go
|
|
| |
|
Member
Posts: 14
| Got fed up and towed it to an Greek mechanic who has nary a computer or electronic tool in his garage.
He called that afternoon to come get the car.
Seems one of the push rods coming out of a rear brake cylinder was installed at an angle which would allow it to push out but due to the angle it would not retract properly.
He leveled it out, problem solved.
I never saw it.
Thanks for all the help.
|
|
| |
|
Expert 5K+
Posts: 8443
Location: Perth Australia | Glad you got it sussed out
Enjoy your car
|
|
| |
|
Member
Posts: 14
| Update: After a day of great driving, the rear driver side locked up again.
Son of a Dutchman.
So we have now turned the drum (it was off quite a bit) and I get the Desoto back tomorrow and we try again.
I'm hoping this will do the trick.
That car wants to roll. I have to get this right.
Must admit my patience is wearing thin.
But again, thanks for the assistance.
|
|
| |
60 Desoto brakes stick
