Drum Brakes Woes

[blueticker17]

I have a 1965 Fj45 with 4 corner drums.
Problem: Brake pedal going to floor.
Solution: Adjust pedal length with the piston on the master.
New Problem: Brakes work great.....until I have driven for 4-5 miles, then it is like they have all engaged and I have to "drag" them all the way home.

If I back the piston on the master back out then the pedal goes straight to the floor and I have to pupm 3-4 times everytime I want brakes.

WHat do I do?
Do I adjust the piston and then when the brakes drag adjust the shoes out so they are farther from the drum?

Any help would be great. I have done a search and not found what I need. Also I did not post on the 45 site because the brakes on a 65 should be about the same and the respnose here is a lot faster.

BTW I have brand new Toyota Master and all 8 wheel cylinders are new. Brake lines are in great shape and hoses are also in good shape. I have bleed the system and it has new brake fluid.

Thanks,

 

[dgangle]

For what you paid for all those new wheel cylinders you could have a real head start on a disk conversion. But that's probably not what you want to hear. One of the happiest days of my life is the day i threw all of the stock drum brake crap in the trash.

Sounds like there is a fine line between the correct push rod adjustment and to little/much clearance. Adjust the rod so there is the correct clearance...you don't want them dragging. I found it impossible to accurately measure the clearance so I did it by the trial method. Adjust, drive 10-15 minutes, jack up one of the front wheels and spin it. Readjust the push rod based on what the spin test found and repeat 10 more X!!

You did not say if you have properly adjusted the wheel cylinders. I would look here next. If they are out of adjustment then it will take a few pumps to push them out enough for the shoes to come in contact with the drums and provide enough stopping force.

You want want to look around a little if you haven't already. This is a regular topic.

 

[45Kevin]

I have a78 fj45. I put discs on the front because of improved braking and it was cheaper that the wheel cylinders. My 45 has a bigger wheel cylinder than the 40's. Now I need to pump the pedal once to get the pressure up. I have bled the dam things several times with no improvement.

Some say that threr is a little ball in the M/C that needs to be adjusted when ging to discs. I haven't explored that yet.

 

[NOJEEEP]

If everything works untill things get heated up a little, then there is usually air in the lines. Sometimes pumping the pedel and cracking open the bleeder isn't enough to get the air out. Pushing fluid from the brake cylinder up to the master cylinder is much more effective and usually solves the problem. It will have to be done at each wheel. Most autopart stores sell a tool that will do this. I made one from a brake fluid bottle by putting a valve stem through the cap with a piece of rubber hose attached. Connect the hose, open the bleeder and squeeze. Don't stop untill the fluid comes into the master cylinder without bubbles. Tighten the bleeder. Never stop applying pressure once you start untill the bleeder is tight. I use a quick clamp for pressure but don't over do it or the hose will pop off. If you make your own, don't forget to take out the valve stem. If you don't use a clamp for pressure, make sure you are ready for a forearm workout. Good Luck.

 

[Pin_Head]

I have to pump 3-4 times everytime I want brakes.

WHat do I do?


,

Properly adjust the rod between the pedal and master cylinder. If the piston does not return fully you will have the problem you describe.


This means the brakes are badly out of adjustment. Cruiser brakes must be manually adjusted every few thousand miles or so.

Tighten each adjuster on all wheels until the wheel can't turn. (some wheels have two adjusters). This centers the shoe in the drum. Then back off the adjuster 3 clicks; just enough so the wheel can turn. The brake shoe will make a dragging noise, but this is normal.


If after you adjust the brakes properly, the pedal feels "spongy", then you may need to bleed the brakes too. You usually only need to bleed them when you either replace them or you run out of fluid in the reservoir.

 

[mhdsummers]

This page might help

http://www.rzeppa.org/tech/brakes.htm

 

[Fast Eddy]

Some say that threr is a little ball in the M/C that needs to be adjusted when ging to discs. I haven't explored that yet.

It's not a ball, it's a residual valve. If you get one your brakes will no longer be unsafe.