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.
I’m new to the forum, and I have a question about a part in the brake system of my 1987 pick up 4x4. I’ve looked all over the internet for an answer and can’t find one, so maybe y’all can help me.
After my master brake cylinder there is a connector of some kind that has 5 hoses connected to it. 2 of the hoses run to the master cylinder, 1 runs to the front driver’s side tire, and the other 2 to the front passenger side. I’ll attach a picture of my best attempt to draw it out.
I’m wanting to replace my master cylinder because I believe it is leaking some fluid, but I want to replace that attachment as well. I think it could be an LSPV, but I can’t find anything about it anywhere. Hopefully y’all can help me out.
Thanks in advance! This is my attempt to draw out the brake system on my truck.
That is part of the master cylinder, this is what you get when you order a new one:
Make sure you use a flared 8mm wrench removing those brake lines after spraying some penetrant like PB Blaster on those threads and letting it soak a bit first.
Last edited by Paul22RE; Jun 27, 2019 at 07:22 AM.
That is part of the master cylinder, this is what you get when you order a new one:
Make sure you use a flared 8mm wrench removing those brake lines after spraying some penetrant like PB Blaster on those threads and letting it soak a bit first.
Thanks! Will do!
So when I get a new master cylinder, that part won’t be necessary anymore? Will I just need to remove it and replace it with a T and another connector?
The piece you are showing below your master cylinder is not an LSPV (load sensing proportioning valve), that is under the rear of the truck and has an arm attached that connects to the rear axle.
What you are showing IS a proportioning valve though.
Thanks! Will do!
So when I get a new master cylinder, that part won’t be necessary anymore? Will I just need to remove it and replace it with a T and another connector?
Oh, if you meant the front brake T-splitter, that is not part of the master cylinder and has to be reused, found this video from someone who deleted their proportioning valve:
My 92 does not have that valve below the master cylinder. I think it's because the master cylinder is a dual piston design that basically takes the place of the proportioning valve. I guess the older models had single piston master cylinders, so they needed the proportioning valve.
That valve is a very important part in case you loose pressure to either the front or rear brakes. You loose pressure say on the front brakes. The little floating piston inside that valve should move over, so that the rear brakes will still have brake pressure. It's a safety thing.
Pretty sure that's how it works because my 240 Volvo had one, but it went even further with the safety net in that there is two brake lines per wheel. The proportioning valve looked like an octopus with all those brake lines coming out of it. Eight brake lines going coming out of the valve.
Last edited by snippits; Jun 27, 2019 at 09:20 AM.
The information I have shows that the valve I found in the link above is supposed to fit 2WD Trucks, so your part number may be different, but they have been discontinued for a while.
Out of curiosity, do you have a Load Sensing Proportioning Valve above and connected to your rear axle?
The information I have shows that the valve I found in the link above is supposed to fit 2WD Trucks, so your part number may be different, but they have been discontinued for a while.
Out of curiosity, do you have a Load Sensing Proportioning Valve above and connected to your rear axle?
I don't know nothing about retrofitting a later master cylinder. If it were possible, there would be a lot of plumbing brake lines. Not worth it my opinion.
When you install the new master cylinder, make sure it's bench bled very good. I would at least spray the proportioning valve down with penetrating fluid, and then oil the outside. Yours does not have a single pole switch on it like my Volvo does, and that switch is where they start leaking. At least I don't see a switch on your valve.
Might want to wire brush the valve too especially at the top there where that one line goes into the valve. It's not looking too good. When I changed out the valve on my Volvo, I sprayed it down every day for three days. I had a good line wrench, and it actually came off fairly easy. These type of valves can be a nightmare especially if the nuts start rounding off.
Last edited by snippits; Jun 28, 2019 at 05:15 AM.
If that part number that old87yota posted is correct, I think I found a new valve that is available from a Japanese warehouse. They are running a 10% off sale right now.
Jun 27, 2019 | 06:05 AM
