Brake Issues

[Ratchetop]

I have been trying to fix the brakes on my deuce. I have a question. Is the vent on the end of the line on the firewall a one way valve or should it vent both ways??
Mine is a one way valve.
The brake pedal will stop but will not return, it like sticks down. Any suggestions would be appreciated.

Thanks

 

[frank8003]

Did you jack and crib it, remove all the wheels and drums and inspect it?
Perhaps one should not begin at the top of the mountain



Lots of mechanisms to repair, replace, inspect
Air over hydraulic, steel lines, rubber lines, springs, fasteners, hold downs, unions, couplings, transfer stays, wire wound steel, inverted plugs ...........

Little upside down wheel cylinders, different brake fluids, master cylinders, squish plates, vent lines, vents and more stuff hidden away as per design. Vents, ALL tied into the ONE, MAYBE .....................
50 years of mechanics working on systems ......................
It is all the one thing to save, repair, to not let fail.
You picked the job.
Enjoy the work

 

[gimpyrobb]

Open the master cyl fill port up and look in with a flashlight. At the bottom of the master cyl reservoir there should be 2 holes. Make sure they are not plugged. Bailing wire should be a good "feeler" to make sure they aren't plugged.

 

[NDT]

Two things cause the brake pedal to return. The pedal itself returns by a spring. The piston in the master cylinder returns due to the fluid being forced back into it by the 6 springs on the brake shoes retracting the shoes and compressing the wheel cylinders. It's also possible that the master cylinder bore is a scored and is preventing the piston from moving freely.

 

[gimpyrobb]

Compensating port! I knew there was a term for that second stupid hole!


The compensating port is used to allow the master cylinder piston to quickly return to the unapplied position, as well as compensate for fluid expansion or contraction from changes in temperature. ... Hydraulic pressure is created by the pressure of the piston on the brake fluid. If the compensating port is blocked, your brakes will not release.

 

[silverstate55]

Compensating port! I knew there was a term for that second stupid hole!


The compensating port is used to allow the master cylinder piston to quickly return to the unapplied position, as well as compensate for fluid expansion or contraction from changes in temperature. ... Hydraulic pressure is created by the pressure of the piston on the brake fluid. If the compensating port is blocked, your brakes will not release.

I have a bunch of torch tip cleaners I picked up from Harbor Freight a while back; I use these to run through the compensator holes to clear any crud. That way I can get the right size to run through every time. Quick and easy.

 

[silverstate55]

I have been trying to fix the brakes on my deuce. I have a question. Is the vent on the end of the line on the firewall a one way valve or should it vent both ways??
Mine is a one way valve.
The brake pedal will stop but will not return, it like sticks down. Any suggestions would be appreciated.

Thanks

Mine does not have a check valve in it, it vents both ways. I did put a small-engine air filter over the end to keep dust & debris out, but still allow it to vent.

Whatever you do, make sure you do NOT connect this vent line to the valve cover downpipe vent near the exhaust; vapors from the crankcase will contaminate your brake fluid and cause all kinds of problems. Keep it venting to just air.

 

[frank8003]

If you do it right you can watch the results of application
and release of the brakes fluid DOT 5 move in and out
of the reservoir to the brake cylinders and back again.
The top of the sightglass is the vent.
View attachment brake reservoir IMG_2208 02212014.MOV

 

[cucvmule]

Did you jack and crib it, remove all the wheels and drums and inspect it?
Perhaps one should not begin at the top of the mountain

View attachment 678955View attachment 678956

Lots of mechanisms to repair, replace, inspect
Air over hydraulic, steel lines, rubber lines, springs, fasteners, hold downs, unions, couplings, transfer stays, wire wound steel, inverted plugs ...........

Little upside down wheel cylinders, different brake fluids, master cylinders, squish plates, vent lines, vents and more stuff hidden away as per design. Vents, ALL tied into the ONE, MAYBE .....................
50 years of mechanics working on systems ......................
It is all the one thing to save, repair, to not let fail.
You picked the job.
Enjoy the work

Enjoy the work.

The reaction of one foot.