What is involved in installing one? ('95 p/u) I think I need one in my truck because when I hit the breaks my rear tires always lock up. Even on dry pavement. It gets scary when it's wet. Do I need a proportioning valve or is there some way to adjust it?
If it is rear drum there is a star wheel that can be turned to losen the brakes up a little. if you backup and stop alot it will adjustit too tight as well. There should be a little oval plug behind mud and debris on the back side of the drum. reach in with a screw driver or brake adjusting tool and loosen wheen. It is in Haynes too. If the new trucks dont have this then disregaurd thanks.
frank-p... right on with the auto adjuster idea, lots of people neglect to realize this.
It would help if I knew if you had the 4-WAL system or the R-WAL system. Is the ABS light on?
To reset the valve, you can take off the rubber caps on the ends of it and poke a wire coat hanger in there. This should reset it if it isn't broken. I have seen a faulty master cylender cause this and the VSS sensor (located on the rear of the T-case). Cloged lines and swelled hoses also do this. You should also check to see if the rear drums are wet. Make sure your calipers aren't frozen (I doubt they would both freeze though).
No matter what you have (R-WAL/4-WAL) there are several different configurations of these systems from 88 to 98, so I can't tell you exactly how to change it. I do know that on my '90 2500 I had to take the whole assembly out (master cyl, P-valve, dump valve) because it was all made into 1 bracket. I had the R-WAL system. The master cylender falls off when you take off those 2 bolts, then I guess they want you to replace everything on the bracket (it is sort-of smashed into place, you'll see what I mean) I decided to grind off the tab that holds The Proportioning valve in place and weld in the new one. Since steel and alumnium don't weld togeather I just put a big puddle of alumnium in there and that held great. If you have any more questions I'd be glad to help, but I can't diagnose this type of thing on the computer. It sounds like you already have a pretty good idea what's wrong though. After I did the job the problem was still there. I then (why not earlier) noticed that the pedal was really squishy. I replaced the master cylender and that fixed it.
I don't have a camera but here is my truck minus the lift and brush guard.
The ABS light is on because I ripped the front end out(SA) so I don't have ABS any more. The dana 44 is totally rebuilt so I don't think the calipers are frozen. I'll try the adjusters and see if that does anything. If all else fails I'll just take it to a brake shop. There's a shop around here that I trust with my they just charge me out the arse so I would like to fix it myself.