jerry507

The title really says it all. I feel like I'm going to die on the freeway braking for some idiot in the not too distant future. But, a little background.

I tore apart my rear drums a few months back and replaced a ton of parts. New wheel cylinders, shoes and all the replacement hardware I could find. They were pretty nasty and not really working like they should have.

Now they work great. Too well in fact, and at any moderate braking I can lock the rear wheels up and fish tail a bit until I back off and regain control. I've left the 300lbs of sand in the back of my truck which no doubt is part of that problem, but soon I'll need that sand again and the problem just needs to be fixed.

The PO lifted the truck quite a bit and did a super janky extension to the load sense rod which I believe is part of the problem. But the LSPV is also completely trashed. The rubber boot is just gone and it's rusted up a ton too.

So what are your suggestions? Replace the LSPV with a junkyard model, replace it with something else, fix the arm with something that makes more sense or just try to actually set the LSPV pressure and hope for the best? Other?

ehenson99

Are your shoes adjusted properly? How many clicks does the E-Brake take until it's fully engaged? It sounds like your shoes might be adjusted too tight or the LSPV is adjusted too high like you said. If I were you I would unhook the rod of the LPSV where it connects to the axle and let it hang down and drive it and see if you get less pressure to the rear. If that helps you are probably going to have to adjust the rod to get a happy medium between the front and rear brakes.

jerry507

Ebrake? Oh, that thing. I don't actually have one. The PO seems to have replaced the entire axle with one from a dually and ditched the rear half of the parking brake cable along with it. I haven't got one from the junkyard to replace it yet

I adjusted the shoes by simply clicking them up until they were sitting against the face and then backing off a turn or two. The auto adjuster may or may not work, tilting towards the not working side.

250000_yota

Knowing what kind of truck this is would help, but I'll fire off blind...

Like stated above, you seem to have it narrowed down quite a bit. Since you don't have a e brake, lift the truck and spin the rear drums by hand to see how tight their adjusted. There should be LIGHT resistance. I usually adjust rear brakes so that they'll free spin 1-1.5 turns. Any tighter and they'll lock up easy. Any looser and they'll delay grab, meaning you'll suddenly feel the truck start braking more about a second after hitting the brakes.

If this doesn't fix it, then move to the LSPV. Do like the previous poster said and let it dangle to simulate a minimal load in the bed.

jerry507

Those are both very good ideas and I think I'll move forward with that. The reason I didn't mention the truck is because, as I said, the rear axle was replaced with one from a dually using the duo-servo style. Otherwise it's a 95 4wd pickup.

1%_Spawn

It sounds like your LSPV isn't working. My brakes lock up the same way (86' 4Runner). I removed my LSPV because it was leaking and damaged and I didn't want to spend the $$ on an OEM unit. I bought a manual proportioning valve from Summit and will install it at the master cylinder when I replace my rear axles. I got the P/N's to order from this site so you should be able to search for them. The valve and line adapters were about ~$70.

warbirdghost

As 1% Spawn said. I would bypass the lspv and put in a manual adjustment valve to the rear. I know some people don't like the idea but I just did it in my 85 and I like it. It's cheap, it's easy. And I also got my valve from Summit.

dvaldi

Might take a bit of searching the Yotech classified or eBay but I was fortunate enough to find a used LSPV for $70 (free shipping) on eBay, mine was shot/rusted.

250000_yota

You said that you did the rear brakes on the truck, so that should mean you know the year of the truck that your rear axle came out of correct? It just helps give all the info you can so that people here can help as much as they can.

mtb83201

How did this turn out? I have the same problem, especially when it's cold and wet outside.

jerry507

The problem is it got cold outside

I haven't looked into it much yet. I'm going to replace the LSPV, but I'll find one at a yard and replace it. Adjustment on the drums were fine, but I'd backed off as 250000_yota suggested.

The axle was from a duo-servo truck, which I believe only came on dual rear tire vehicles. I was able to find it from a late 80's pickup, I don't remember which year. Nothing from like 91-95 was correct. Very irritating!