M1009 Continuing Brake Issues

[1dcorbin]

After a right rear brake lock-up, observed bad brake pad wear, and the effects of PA road salt on my rear brake components, I had new drums, pads, cylinders, and lines installed on my M1009.

Now, the first few miles of a road trip are awesome, the ride is smooth like a new car. As time progresses a vibration begins. I also notice that I have too much braking force on the rear in comparison with the front. That is, in a quick stop, the rear wheels slide and the front brakes just seem to keep rolling.

Again, as the ride progresses applying the brakes gives me feedback like a vehicle with bad rotors.

Is there an adjustment that needs to be made? Do I have another defective component somewhere?

As always, thank you for your help.

 

[porkysplace]

Did they use DOT 5 brake fluid ?

 

[1dcorbin]

I don't know; but, I will check.

So you think that may be the problem?

 

[porkysplace]

I don't know; but, I will check.

So you think that may be the problem?

Dot 3 and DOT 5 don't mix it turns to a jelly like substance.

[h=1]Mixing Brake Fluids[/h]
[h=1]Brake fluid -how to tell which kind you have DOT 3 or DOT 5[/h]

 

[1dcorbin]

If the wrong fluid was used, is there a method / procedure for flushing out the system; or, do I have a lot of scrap parts at this point?

 

[Ilikemtb999]

I've heard you can run brake cleaner thru open lines to clean them out. Or just a good ol flush of dot 5. If you need it locally I've found advance auto carries it and you can use an online coupon and pick up in store.

 

[1dcorbin]

Thanks for the info. We'll give it a try if that's the problem. Otherwise, I'll be humbly asking for more help.

Thanks again!

 

[dmetalmiki]

If the fluid is OK, clear, Is the vehicle fitted with a restrictor (brake check/balancer) to the rear wheel brakes? (usually on top of and center of the rear axle) I believe the are (should be(and)) I would be checking that first. Let us know what sorted the problem when you fix it. And CHECK the master cylinder as the brakes "cross over" for duel braking. (no prize for guessing where ONE of those lines goes (directly) to. Yep, the problem wheel?

 

[german m1008]

The Break proportioning valve is mounted on the Inside of the frontbumper....
from there goes 1 breakline to the rearbrakes....

 

[dmetalmiki]

There Ya' go then, (I'm not at all too familiar with those trucks) You can now trace from that unit, (and the master cylinder itself) and I reckon you will soon have the problem sorted out. Please post up your findings.

 

[1dcorbin]

There Ya' go then, (I'm not at all too familiar with those trucks) You can now trace from that unit, (and the master cylinder itself) and I reckon you will soon have the problem sorted out. Please post up your findings.

When we [the mechanic and I [?]] get it figured out [due to your input], I'll post the results.

And, thanks again!

 

[cucvrus]

This is an easy inexpensive fix. And might I add a great upgrade to the truck. It is an opportunity that I take with every CUCV I buy. First buy a re manufactured master cylinder, front brake calipers and 2 new wheel cylinders. You will have to pay a core charge on the calipers and the master cylinder unless you opt to buy new parts. I do that at times also. But before you begin flush out the entire brake system with dot 5 fluid until it reaches the bleeders all the way around. Do a full inspection of the steel and rubber brake lines. If they look iffy change them. Now is the time. Also double check the hydraulic brake booster at this time. Look under the dash. Is any fluid leaking into the cabin? If so that needs changed. When you remove the master cylinder check and see if you have a power steering fluid in the booster area. You may have brake fluid there also. That is up to you to discover what fluid you have leaking if any. The rest is self explanatory. I recommend a little vac brake bleeder pump. But the old pump em up and hold works also if you have a competent helper. They are getting hard to find. Check your rear drums see if the are out of specs or bell shaped. New drums and rotors are inexpensive also. If you change everything yourself supplying labor you will spend less then $300. and have a truck that brakes like new. That price does not include the brake booster if that is an issue. But I doubt it is. Good Luck and ask more questions if you need to know. No dumb questions are asked.

 

[1dcorbin]

Thank you!

 

[porkysplace]

I think first he needs to talk to the guy that did the brakes and confirm what brake fluid was used . I put the brake fluid question out there as it sounds like he took it to a repair shop not familiar with military trucks . And when the OP mentioned "pads" I took it he meant rear shoes as there has been no mention of any front brake service being done . If the fronts were not serviced it could just be bad calipers.

 

[cucvrus]

If you are that close and live in PA. Stop by and I can assist you with this job. I do know somethings about CUCV's. Or just drop it off and come back when it is completed. My services are not free but they are affordable. Good luck either way.

 

[1dcorbin]

The mechanic was out of town, but got back to me this evening. The first glitch that we have is with the use of DOT 3 rather than the DOT 5. So, if the system was purged and DOT 3 was used, what are the consequences of that?

The emergency brakes were just replaced. But, the thought is that they may still not be releasing correctly and may be hanging up the right rear as before.

It's going back to the shop for a look-see tomorrow.

 

[cucvrus]

The right rear hanging up could be several things. From axle seal, bad wheel cylinder leaking to bad hardware. I opt to just start over and change everything brake related. It saves me a lot of down time and I even do it on trucks I use as off road only vehicles. I replaced all brakes seals and hardware on Terminus M1009. check out that thread and you can see the rear brakes, hardware being replaced. Thank you for the PM. Let me know if I can help you out. Good Luck. I don't feel mixed fluid is causing the issues you are describing.

 

[porkysplace]

This is an easy inexpensive fix. And might I add a great upgrade to the truck. It is an opportunity that I take with every CUCV I buy. First buy a re manufactured master cylinder, front brake calipers and 2 new wheel cylinders. You will have to pay a core charge on the calipers and the master cylinder unless you opt to buy new parts. I do that at times also. But before you begin flush out the entire brake system with dot 5 fluid until it reaches the bleeders all the way around. Do a full inspection of the steel and rubber brake lines. If they look iffy change them. Now is the time. Also double check the hydraulic brake booster at this time. Look under the dash. Is any fluid leaking into the cabin? If so that needs changed. When you remove the master cylinder check and see if you have a power steering fluid in the booster area. You may have brake fluid there also. That is up to you to discover what fluid you have leaking if any. The rest is self explanatory. I recommend a little vac brake bleeder pump. But the old pump em up and hold works also if you have a competent helper. They are getting hard to find. Check your rear drums see if the are out of specs or bell shaped. New drums and rotors are inexpensive also. If you change everything yourself supplying labor you will spend less then $300. and have a truck that brakes like new. That price does not include the brake booster if that is an issue. But I doubt it is. Good Luck and ask more questions if you need to know. No dumb questions are asked.

You left out a key compoment that will cause brake locking is worn backing plates.

 

[cucvrus]

I never seen that on a light duty truck. That is a 1 in a million shot. If that is so. Any 1/2 ton 2WD truck will work and if you can not find any i have lots of them.

 

[porkysplace]

I never seen that on a light duty truck. That is a 1 in a million shot. If that is so. Any 1/2 ton 2WD truck will work and if you can not find any i have lots of them.

I've seen quite a bit of it especially with worn drums.