Fixing My Brakes: Part 1 - LSPV Delete
My 2000s brakes seemed to degrade over the last year or two to the point where I wasn't comfortable driving with my new child in the truck. It would stop, eventually, it just wouldn't seem to bite. I'd installed 13WLs and good rotors and pads several years ago (which are a good bit bigger than the stock 13WEs that came on my truck originally) and everything there seemed ok. So I put in new shoes and drums and adjusted the brakes to make sure they were engaging properly… a bit of improvement but nothing major.
A lot of reading and inspection later I determined 3 things: 1- My rubber connector lines at the front and rear were now 20+ years old, and were possibly flexing when the brake fluid was pressurized. It was time to replace them. 2- Several people had reported the LSPV (Load Sensing Proportioning Valve) not working properly and replacing with a manual valve had improved it. And 3-I'd never performed a total flush on the brake fluid before. It's possible some old fluid was still inside and was causing problems. I decided to tackle all 3 items at the same time; the stainless brake line replacement will be addressed in Part 2.
Tools and supplies needed:
Brake Bleeding Tool (helpful if doing this solo)
Tie Plate / Bolts to hold valve in place
So I started by draining off as much of the old fluid as possible using a turkey baster. Reminder, the little mesh filter inside the tank can be pulled out allowing you to suck most of it out. I refilled the tank to the max with new fluid and left the cap slightly off allowing it to vent as fluid would be purged through the system; my old fluid was a dark brown while the new fluid was a light amber, so I could easily tell during the brake bleeding process when I had gotten to the new fluid.
I then removed the LSPV return line using the 10mm wrench from the bottom of the master cylinder and installed the plug with the 5mm allen. No fluid drained when I did this but keep some towels down just to be safe. (Picture #1)
I then went to the back axle and started working on eliminating the LSPV. Go ahead and break free and remove the 3x brake lines running to the valve using a 10mm open ended wrench (Picture #2). Gently push them back out of the way to not crimp the lines. Have a catch pan under to catch the dripping brake fluid (some people might not want the fluid to be dripping, but since I was doing a full flush anyway, it just saved me some time later. It's also why all this work starts upstream and goes downstream).
3x 12mm bolts hold the valve into the frame and 2x more 12mm hold the other end to the axle. Go ahead and remove all the bolts and jiggle the valve to remove it from the frame. Chuck it out of the way
At this point I connected in the Wilwood valve. I had to make some slight bends by hand to make this happen, but just go slow and it should fit fairly easily. At this point I bolted in my tie plate through a hole in the frame; I used bolts and nuts I had laying around that fit...I'd suggest prefitting these together before going under the truck in case you need to drill. I used a second tie plate as a giant washer since the hole in the frame is rather large. I’ve seen other people reuse the bolt points where the LSPV was originally; just route it to a secure location that is the same height as the frame and you’ll be ok. I then bolted the Wilwood valve to the tie plate and the LSPV delete is complete. (Picture #3)
If all you’re doing is a swap for an LSPV to a manual valve, proceed with bleeding the your brakes in the proper order (passenger rear, driver rear, passenger front, driver front), and then start adjusting your valve. The easiest way is to drive and slam on brakes; if your front is not diving, start adjusting the pressure to push further up front. Don’t go too far as you’ll start feeling your tail slide; if you do, back it down a little.
I, of course, am not done; I went on to replacing my brakes lines, which you can find in Part 2.
