I was wandering if anyone out there has ever heard of or even done this. Taking the proportioning valve off your brake system and put a manual valve on the rear side and adjust it accordingly. This is on a disc brake front and rear system. In doing this you are improving your braking power with out having to spend a lot of money on like hydroboosts and what not. Cause everybody knows that we all would like to stop quick with our big tires.
Improved braking?
- Thread starter BEHERSKE
- Start date
I had to put one on a muscle car I had since the rear would over power the brakes. The front would lock up and the rear tires would spin. If your front and rear brake the same it wouldn't help since the valve adjusts the pressure to make the braking even.
- Location
- Sandy, Ut
So your looking to install a manual proportioning valve instead of the pre-set one? It could help out your braking and they are pretty cheap in comparison. I use them all the time on disc brake conversions, rarely to improve the braking per say, rather just control it. I think alot of vehicles would benefit from it, especially those that have far different loads and dynamics than the stock vehicle the pre-set proportioning was designed for.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
Well, for what its worth, I took the proportioning valve out all together on my YJ (I have an 8.8 in the rear with discs). I was sick of the front locking up while the rear didn't even feel like they were grabbing. I noticed it mostly in the snow. I would slide forever. It seems to have helped.
Yeah I am thinking of removing it completely and just putting a manual set valve on the rear disc. My thinking is that it will help stop better thats all i just can't afford to throw hundreds of dollars at a hydroboost system of some kind. Cruiseroutfit have you done what you were talking about in a TJ and if so how has it worked?
- Location
- Sandy, Ut
Nope, most I've done on a TJ has been a headlight bulb... seriously
All the proportioning valve setups I have done have been on Land Cruisers... but they all worked as planned. Worst case you end up setting the manual valve back to a setting close to the stock proportioning... all your out is the cost of the valve and your time.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
This isn't advisable. A prop valve works under heavy brakign to distribute the breaking load. You won't see a difference in normal day to day driving. So I'd work on getting a manual valve put back in.
Also, prop valves can stick all front/all rear, that could have been what happened to yours. Drum breaks don't move much fluid and if the fluid is old and etc, it can corrode into a stuck position causing the loss of brakes.
- Location
- Sandy, Ut
Sorry, I don't sell them.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
In that case, I do. I have Baer and Ford Racing; either is $50. I prefer the Baer, because it does come with popular fittings. The Ford Racing looks better, though. Summit Racing has a Baer look a like for like $35.
I am going to dissagree with everone that has answered so far. The device you are thinking of removing does more than act as a proportioning valve. It is called a comination valve and includes safety features you may someday wish you had not removed. You will not gain any braking power by removing it!! If your Jeep came with rear disc brakes standard then the valve you have is probably the best brake proportioning setup you will find. If it came with drums and you converted to rear discs then the best thing you could do is find a combination valve that is for a four wheel disc setup like this one http://www.mpbrakes.com/products/product-detail.cfm?product_id=613.
- Location
- Sandy, Ut
Could be true for a Jeep... but not in a LC, they act solely as a proportioning valve.
What exactly is "safety feature"? A check valve?
Pressure diferental switch and metering valve. Your probably not going to die or kill someone if you replace it with a manual valve, but I don't see a reason to take it out of the system unless you can't make it work.
- Location
- Sandy, Ut
Hmmm, not sure how a metering valve differs from a proportioning valve
In fact both of those names could be used for a standard proportioning valve, it both meters flow and differentiates pressure What does the "pressure differential switch" do? I assume it dynamically changes brake pressure to the wheels with zero driver input? Kinda neat... I'd be interested to know what it does though, not just what its called
Land Cruisers never had such a beast (well not on the older units anyhow, newer ABS models have all sorts of features). The do have a LSPV (load sensing proportioning valve) that changes the rear braking based on the load over the rear axle, seems to work fairly well for stock vehicles, its often ditched in place of a manual valve in a build up.
While I can agree with not removing a safety feature... many times they were designed for just the stock vehicle, lift them, load them differently and run far different tires and suspension and they might become an unsafe feature
Hmmm, not sure how a metering valve differs from a proportioning valve
What does the "pressure differential switch" do? I assume it dynamically changes brake pressure to the wheels with zero driver input? Kinda neat... I'd be interested to know what it does though, not just what its called
Land Cruisers never had such a beast (well not on the older units anyhow, newer ABS models have all sorts of features). The do have a LSPV (load sensing proportioning valve) that changes the rear braking based on the load over the rear axle, seems to work fairly well for stock vehicles, its often ditched in place of a manual valve in a build up.
While I can agree with not removing a safety feature... many times they were designed for just the stock vehicle, lift them, load them differently and run far different tires and suspension and they might become an unsafe feature
Metering valve just delays puting pressure to the rears untill the fronts are pressurized (maybe the otherway around it has been a while since I have reasearched my rear disc conversion) The switch just lights the brake light on the dash when there is a problem. Like I said not a big deal.
- Location
- Sandy, Ut
Ah, that makes sense. Some of the newer (late 70's and newer) Land Cruiser ones have the pressure switch built into the master, but that is a feature I think is important to have
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
I think any modern braking system is going to have this combination valve in place, LC or Jeep or GM or Audi, or? Like Bob said, it's there to prevent the rear brakes from bleeding the system dry, or the front. Say your brakes develop a leak, this combo valve to stop the fluid goign to the back brakes. Or vice versa. The manual prop valve will not do this. I believe this is a NHASTA safety feature that is required... Maybe LC's don't have it in the prop valve, but I'm sure they have it somewhere...
Just FYI, your Wrangler uses the same prop valve and master cylinder regardless if it has disc/drum or disc/disc. If by removing it, your brakes worked better, it was not functioning correctly.
Just FYI, your Wrangler uses the same prop valve and master cylinder regardless if it has disc/drum or disc/disc. If by removing it, your brakes worked better, it was not functioning correctly.