I have a 1987 W150 w/225 and manual. I've had nothing but crummy brakes since I got it and I've been through just about everything so far. As of now I've done the master cyl, rear wheel cylinders, rear hardware and shoes and I've bled the whole system thoroughly several times. The front calipers look good, not sticking and pads are still ok. Today I took the rear brakes apart again because they started making awful noise a few days ago and found out that the self-adjuster pawl on the right rear had fallen out and was scraping around in the bottom of the drum along with it's spring. This time it went back together just fine(I vaguely remember that when I did the rears in January that one of the self adjusters didn't feel right, but after fiddling with it and re-assembling it a half a dozen times, I just threw up my hands and went on with the job. I guess I won't do that again.) I got my brakes adjusted till I could just feel the shoes contacting the drums then I put everything back together again. This time when adjusting the brakes (backing up and hitting the brakes) the brake light comes on every time. There is plenty of brake fluid and the brake light does not come on when braking forward. WTF? The brakes now feel better than they ever have, almost up to mediocre, but the brake light seems to be wanting to tell me something. Should I just tell it to shut the hell up? Also, no matter what I do with the parking brake adjustment, the parking brake ends up worthless. I had it adjusted alarmingly far in and it nearly worked two or three times, but then it went right back to worthless. I'm a little concerned that if I adjust it too far, it will wear out the brakes prematurely and still not provide any parking brake..y...ness...?

As Ettoire Bugatti may or may not have said, ''My cars are designed to go, not to stop." Only a slant six 4x4 isn't exactly designed to go, either. At least not in the sense that Ettoire meant...

 

your brake light could be coming on because of the park brake lever dropping. how well does that lever on the side of the frame move. i know you almost need to get it moving freely if you want to get everything working good. there is no such thing as adjusting it too much.

 

I forgot to mention that the brake light does not come on when I step on the parking brake. I haven't looked into why it doesn't yet. The adjusting mechanism and associated lever seem to be functioning smoothly. I'm afraid that I will overadjust the cable so that it causes the brakes to drag when the parking brake is released. Are you saying that this is not possible?

 

it is possible but not likely. you will know when you press the peddle whether you have over adjusted it or not.
this is how far adjusted the one on my 81 is.

 

I can't feel your brakes so I don't know if they are right or not. What you have to remember is that the brakes on our trucks were considered adequate back when they were made but by todays standards they are woefully lacking. My parking brakes will stop my truck from moving even under power in drive. They will not hold nearly as well in reverse. This is because of the design. I believe I am quite safe in saying that anyone that has bled the brakes in our trucks will tell you that they are extremely hard to get bled properly. From what you have said I believe there is still some air in the system.

The brake light inside the truck is operated by a switch that is activated by the brakes hydraulic system. The e-brake is mechanical and not hydraulic so that light will not operate when using the e-brake. The light is there to tell you when the system is not operating properly. It is activated when there is an imbalance at the metering valve. There are 3 ways to bleed brakes: pressure bleeders, peddle, and vacuum. What are you using?

 

To be safe, you might take it to a local brake shop and have them bleed it for you using their vacuum bleeder. I had a Chevy truck once that I could not get the brakes to bleed right on no matter how many times I tried using the old fashioned way, took it to One Stop brake Shop in alb and they bled them and they worked like a race cars brakes! They only charged oe 20 dollars and I wish I had dome that in the first place instead of getting all frustrated doing it (trying it) so many times myself. Now when ever I do brakes on anything if it needs the brakes to be bled I get them "good enough" and drive it to OSBS to be power bled.

 

Well, I looked into why the brake light doesn't come on when the parking brake is set - (drum roll...) there is no electrical switch on the parking brake system. I suspect that the reason that the parking brake never worked before had a little something to do with the self-adjuster parts falling off...

I did get the parking brake adjusted so that it kind of works, I guess I could screw it down some more, but that's not my main concern with the brakes.

Today the brake warning light came on completely and is now on all of the time. The brakes have always been crappy on this truck, so I don't know what they are supposed to feel like when operating correctly. I am beginning to suspect that it is a problem with my bleeding technique. I have been using the two person/pedal approach and as I recall, I have never been totally convinced that the rear system is bled right. I have run a pint or more through clear and just as I am about to call it good a bubble or two will come though. I finally convinced myself that this was because of a leaky bleed screw, but that doesn't really make sense.

When you say the vacuum method do you mean with a mity-vac hand pump? I've tried that before and found it highly messy and ineffective, but I don't remember if I ever tried it on the truck.

Is there an easy way to remove the balancing valve from the system? It seems like I read somewhere that these never did what Dodge wanted them to do and that they're more of a nuisance than they're worth. I assume that the brakes would bleed just fine without that part in the way.

 

Also, I forgot to mention, there reservoir is full and I can find no leaks in the system.

Also, SEAL, it doesn't take much to prevent my truck from moving forward under full power, I'm more worried about it rolling back under it's own not-insubstantial weight :-)

 

i think the only thing left to try is disconnecting the wire from the proportioning valve. that should get the light to stay off. if it stays on i would consider looking at the electrical somewhere.

park brakes don't really work that great in reverse. i know i have backed up with mine on before but when i went to go forward it would not move.

 

I use the vacuum method for bleeding brakes and my mity-vac hand vacuum pump as the source. I use a pint mason jar as a collector with a lid that I installed two barbed hose connectors to. You should also keep the jar higher than the cylinder being bled. Finding a tight fitting hose for the cylinder bleed valve is the key. Pressure and vacuum bleeding work much better than peddle bleeding because you can keep the fluid and the air moving from start to finish so that the air cannot move backward in the higher parts of the brake system when you are resetting the peddle.

The proportioning/metering valve is necessary in the system. It serves two purposes. It delays the front calipers until the rear brakes have contacted the drums so the front brakes don't do all of the work and it also lessens the amount of pressure applied to the rear drums to prevent rear brake lock-up. If you replace the valve be sure to get one that provides both functions.