When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
With the new wheels and tires the back wheels locked right up. The truck does have a lift 2-3" so I might make a little bracket 2-3" and see what happens.
I finally got under my truck to take a look at this LSPV situation. Upon closer inspection the LSPV was caked in some sort of coating (undercoating?), but I was able to peel most of it off. The boot is in good condition, no cracks or holes. The bleeder valve had that coating on it, so I suspect the LSPV has never been bled.
**Side story: We had the rearend rebuilt quite a few years ago by a shop I was not impressed with at all. Not long after getting the truck back one of the rear wheel cylinders was leaking fluid. Turns out some idiot put the seals/cups in backwards when they put new kits in the wheel cylinder. So, I've never bled the LSPV, and I am very confident that shop didn't either.
I am hoping that if I bleed the LSPV it will resolve my problem. Any thoughts?
The load sensing lever was not tight against the LSPV (ie there was no tension in the lever). So that is good. It is hard to see though, since the boot is in the way.
I removed the load sensing lever from the system, just to get a closer look at the LSPV. It was wet inside the boot, pretty nasty gunk build-up actually. Its hard to tell if it is brake fluid or not. The bottom of the LSPV was wet also, which makes me think it is brake fluid. Not good. Its not like I am loosing brake fluid though...I can't remember the last time I've had to add any fluid to my reservoir.
Lastly, I was able to look at the LSPV piston while someone stepped on the brakes (hard). The piston moved down as the pressure built up in the back, about 1mm. Great! Looks normal. When they let off the brakes, the piston moved down farther (an additional 1mm), just for a split second, then went back up to its normal position.
I thought the piston moving down (for a split second) after the brakes were released was odd. I thought but could it be from the fluid flowing out of the rear brakes...but it seems like once the valve is closed (brakes fully applied), physically the piston should not be able to move down anymore? Has anyone else witnessed their LSPV piston moving like this? Is what I witnessed normal?
I am going to put it back together like I found it, but I will bleed my LSPV and see if I notice any difference. I am hoping I will find air in there! First, I am going to take it for a drive w/o the load sensing lever installed...and see if I can get lockup. If I can, that will tell me a lot.
Interesting I made a bracket for the part that attaches to the axle. I attempted to put it back in it's stock location but it did nothing for me. The rear end will still lock up. I also installed a new slave cylinder maybe I got air in the lines and that is what is causing my lock up problem. I'm going to bleed mine also and see if it helps. Thanks for taking it apart and posting pictures.
I am hoping that if I bleed the LSPV it will resolve my problem. Any thoughts?
When they let off the brakes, the piston moved down farther (an additional 1mm), just for a split second, then went back up to its normal position.
I thought the piston moving down (for a split second) after the brakes were released was odd. I thought but could it be from the fluid flowing out of the rear brakes...but it seems like once the valve is closed (brakes fully applied), physically the piston should not be able to move down anymore? Has anyone else witnessed their LSPV piston moving like this? Is what I witnessed normal?
Yeah, bleeding the LSPV might help, if it needs it.
About the piston travelling down after the brakes are released, that might be explainable. It could be from the force of the brake shoe return springs pushing fluid back through the system towards the master cylinder.
About the piston travelling down after the brakes are released, that might be explainable. It could be from the force of the brake shoe return springs pushing fluid back through the system towards the master cylinder.
That's exactly what I was thinking.
I bled my entire brake system, and unfortunately I didn't see air anywhere. I was hoping I'd get something from the LSPV.
I installed the load sensing lever temporarily without the boot. I do have a gap between the lever and the LSPV piston (truck unloaded). About 1 mm, just like it should be.
I am going to turn my attention away from the LSPV and focus on the rear brakes. I have a kit for the rear to replace all the springs, etc...as well as some new shoes.
I just think its odd that I experience these weird braking issues when its wet out/moisture in the air. I don't see the LSPV being affected by this...but if something is up wth the brakes themselves, that might explain it. I have noticed once in a while, while backing up an braking, there is a snapping or clicking from the rear brakes...like something is shifting. From the FSM, this can be caused by the shoes binding on the backing plate. But, I don't hear it when moving forward.
I tried messin with that thing too, came to the conclusion that its too much of a pita and id rather just have it manually adjustable, this is how it works for now till i get a cleaner turnbuckle.. No more rears locking up in the rain.. as long as you have some sort of way of adjusting it, it doesnt really matter how you keep it up though..
12-17-2010, 12:32 PM
