Brake Proportioning Valve

In a non-ABS vehicle, with a defective brake proportioning/metering (combination) valve and it is not readily available, then, can that valve be deleted, bypassed or replaced with a universal part and is it really important that the rear brake hydraulic pressure be less than the front pressure or zero during emergency stops??? Is there a simple safe way to fix this? (2000 Kia Sportage)

Either find the part at a junkyard or sell the car for scrap.


Yes. Such a part exists.

YES!! The taillights will pass the headlights if the rear brakes lock first.


Reply to (old_mopar_guy): Junkyard part may be bad too? I hope to sell this Kia for $1000 to $2000, instead of $150 scrap price. I’m hoping for a 3rd repair option, but thanks.

Reply to (Tester): I just checked, has part for $300, 30% value of car. I’m hoping for a less expensive solution. But, may be a last option, thanks.

Reply to (Mustangman): Thanks for confirming the safety issue. And did you suggest a universal part is available, (perhaps Dorman 905-953) 4" long small cylinder, in line with the rear brakes perhaps metering that rear pressure? Or is braking balance more complicated?

Notice I did NOT suggest a part… Specifically because it IS more complicated than the device you posted. The “universal” part requires knowledge of how the brake system works, the car it is being installed in and then testing the car so the part can be adjusted properly. Not something a chain brake shop nor a basic DIYer is competent to install and set properly.

Tester gave you a link to the proper replacement part. That is the best, safest, solution to your problem. Either fix it correctly or scrap it.

Do NOT kluge safety items! The life of the buyer and your liability in that transaction depend on it.

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Just to chime in on the importance of not allowing rear brakes to dominate. Some years ago I was having trouble with the rear brake shoes on my Park Ave. Seemed like when wet or humid, first application of the day they would lock. So I’d drive a block and hit the brakes to make the turn and it was very intimidating when the rears would lock. There was literally no braking or stopping and the rear wheels would just slide. New brake shoes took care of it.

I would rather have zero rear brakes than have the rears the dominant brakes. But yeah, comes a point where a car becomes obsolete if parts are not available.

Those of us who ride bicycles know the importance of proportioning the brake force, fore vs aft. Very easy to loose control otherwise. I expect it’s even more important with car b/c of the speeds and weights involved. You’ll have to find the correct replacement part. $300 doesn’t seem that much out of line. $300 is certainly a lot less than buying another car.

Why do you think the problem you are having is caused by the proportioning valve? In my diy’er experience I’ve never had a problem with that part. If it is the problem, likely some grit is clogging one of the ports. I’m wondering if it can be cleaned and returned to service? Does a proportioning valve have moving parts? I’ve always thought the proportioning was controlled by orifice size inside the proportioning valve…

You plan to sell a 22 year old Kia with who knows how many millions of miles on it for $1-2,000? Nobody in their right mind would give you that amount of money for a used up old car.

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Doesn’t seem way out of line to me, given the Covid situation. I wonder what it on-line survey price for that car is these days? Here in Calif ownerwould get close to that amount from the state, just by junking it.

How did you break a brake proportioning valve?


In states that are not California, like New Jersey, we don’t pay people to junk their cars.

I wonder if paying folks to junk their cars results in increased car sales? If so, I can see why dealerships/manufacturers might lobby the state’s politicians for such a thing. By “lobby”, I presume you know what I mean … lol …