New FJ40 owner, newbie brake drum question (1 Viewer)

[Skystar]

Hello everyone,

My wife and I just purchased our first FJ, a '75. One of the issues the PO disclosed was that the brakes required to be pumped twice to stop effectively. He delayed the sale of the vehicle so he can try to figure out the cause. He stated the rear brakes were stopping fine and the issue is with the front brakes. He bled them, and also changed the master cylinder. Still had the same issue and he said the wheel cylinders may need to be replaced/rebuilt. I told him I'd take it from here if he was willing to bring the price down which he did. I then took it to a brake shop who bled and adjusted the brakes again, but the issue was still there. They confirmed the rear brakes were fine, and also said the wheel cylinders were also OK. The tech then told me the front drums were oversized and not to spec, which is what may be causing the adjustment issues.

So searching through the forum I learned most double pump problems may be adjustment issues, and I may just try to adjust them myself. I've been looking for a good pair of drums as well. I have done light mechanic work on smaller cars (suspension, alternator replacement) but never have worked on brakes. Has anyone ever heard of oversized drums? Maybe the PO was not aware someone had changed the drums somewhere down the line? Are the later model drums slightly larger? I'm trying to figure out where they may have sourced the larger drums.

Just trying to get an idea before I dive into this. Thanks!

 

[bsilva132]

75 was the last year for front drum brakes (in the US at least). If you can't get what you have to work correctly and before you spend too much money trying to get the fronts to work properly, I would seriously look into doing a minitruck disk swap.

 

[Skystar]

Thanks, I have yet to spend anything on correcting the issue, and the used drums I found for a great deal. Anything more I would probably start looking into the disc swap.

 

[igotta40]

What he probably meant by 'oversize drums' is that they have been resurfaced and/or are worn past their tolerance limit. New ones are available. But you are on the right track, the problem is the wheel cylinder adjustment. A factory service manual (available item) or even a Chilton's manual describes the procedure in detail

 

[Skystar]

Thanks, so would getting a pair of drums (that are in better condition than my existing drums), and proper adjustment solve the issue? I'm wondering if the worn drums were the problem this whole time. Thanks

 

[ducktapeguy]

If it were me, I'd start tearing into the braking system and see what's going on first. It's good practice anyway. If it were just a wheel cylinder adjustment or out of spec drum, I would hope that the brake shop would be able to figure it out when you took it in. You could try swapping the drums front to back as a quick check.

If you've never worked on drum brakes before, it's really not that complicated. Do one side at a time so if you forget how things go back together, you can always look at the other side. Once you do the first one, the rest of them will be easy. Even though the PO said he went over some of the part, brakes are too important to rely on someone else's fix. Especially someone who's just trying to slap it all together to sell the car. Tearing apart the brake system is the first thing i do when getting a used car, even if everything was rebuilt the week before. You'd be amazed at what some people will do for a "temp" fix.

 

[Ron B]

Use the search function. Alot of threads on the cylinders holding air even after bled. Certain way to do it to get all the air out.