Do I relocate it or delete it? Either way how do I go about doing it?? http://personal.utulsa.edu/~nathan-buchanan/93fsm/brakesystem/12loadsens.pdf
I'll take a pic of what I did tomorrow but I basically cut the rod off and then just made it a manual adjust valve.
thats what i did... im clipping the rest of the attachment points on the axle later tomorrow. from what i understand you can delete the bpv by getting an adjustable one from summit, or get a factory run one from an 86 or earlier that is run under the brake master cylinder.
That's correct. I'm running a Summit unit. But it involves removing the return line to the front brakes.
I deleted it. Entirely. The brake line that runs to it can be deleted. The tee fitting can be deleted, then the line that supplys the tee and the coupler for the rear can be joined. This thing only works when the bed is loaded, it changes the brake fluid pressure due to the angle of the rod attached to the lspv. You wont have any weight back there, ever. Your bagged and a hole in the bed. Drove my truck for a year and never had any complications. Period. --Mike
Um. The LSPV works anytime the bed ISN'T loaded. When the bed IS loaded, it allows more brake fluid pressure which results in more braking action. I understand that you didn't have any complications, "Period.", but this is bad advice to delete it totally and not put any restriction in it's place. Drum brakes are self-actuating, so if you send them the same pressure as the discs up front, they will lock up under a panic braking situation. And not having weight back there makes the situation worse. Not cool. If you want to take that risk on your own truck, cool... (unless you hit me). But don't make that recommendation to others. It's there for a reason, don't put their life or others on the line over a $35 part.
I initially cut the rod and mounted a turnbuckle under the bed but that looked rather ghetto so I machined an aluminum piece that replaces the arm completely. It's shaped like an upside down top hat and has a 1/4-20 bolt and lock nut in the center for setting it. I'll try to get a pic of it tonight. Pretty simple to make and alleviates all the LSPV issues people have with lifting/lowering or super flexy suspensions. Clean install. No re-running brake lines. No buying a needle valve.
LSPV Mod It doesn't look aluminum but it is. It's just seen years of countless mud & yuk coatings. I wasn't sure how well it was going to work so I used soft metal for easy machining. It really should be made out of steel so the bolt don't stick from dissimilar metals, but I never adjust it.
Why not just bend the rod (which is what I was planning to do when/if I finally get my lowering blocks)? Edit: I guess I asked the same question here: http://www.toyotaminis.com/forum/su...oad-sensing-brake-proportioning-valves-19724/
You can. Most guys want to just cut it out. Bending the rod, or modifying the lower mount is the best way to go about it. It retains factory purposing.
The stock arm/hinge is designed to work within the stock range of suspension travel. When that range is changed, factory purposing is defeated. In cases on this site where stock travel is decreased, for it to properly work as factory purposed, you'd have to design a cantilever type of fulcrum that allows the LSPV pin to travel the same proportional distance it would throughout the stock suspension travel. The cut rod & turnbuckle thing worked for years for me before I got the idea to make that part. That rod is hardened, making it difficult to bend to the right angle or saw through with hand tools for the average DIY'r. (grinder w/ c/o wheel is your friend here) Even with a bent arm or/and an adjusted bottom mount, at -3" in back, there's not enough travel to actuate it properly. All you can do is bend or adjust it enough to not lock up the rears on panic stops.