Pressure Regulator Valve


Jun 3, 2001
Can you get to the pressure regulator valve with the tranny in the car? If so then how? I want to make sure that it is moving freely.

Pull the pan and look at the underside of the pump on the driver's side. There is a bore with a retaining ring visible. Remove the retaining ring and you'll be able to get to all of the components in there. See the attached photo.


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Make sure all the parts are oriented correctly. It's possible to put the Reverse Boost valve in upside down.

Is there a particular problem you are chasing down?
Yes Greg, thanks for replying again.
After installing a valve body kit my shifts have not been firm at all. They kind of slide into gears on the 1-2 and 2-3, and flare up as it shifts. This is only when you start to get into the pedal. When not giving too much throttle it still doesnt shift firm, but you can feel it a little and the shift is smooth. It almost feels as if the shifts are coming in too early, as oppose to building up RPM and then shifting. I can shift manually, letting the RPMs build, and the shifts are not hard but are smooth, does not flare up at all.
I have taken the TB out 3 times now just to make sure everything is moving ok and all in place correctly. I cant find anything wrong. The last time I was in there I took the retaining clip off that you mentioned for the pressure reg. valve but couldnt get the assembly to come down, it did move up and down though, so I knew that it wasnt stuck solid or anything.
Any ideas.
I will probably put a pressure guage on it if I can get a hold of one. I was thinking maybe the pump is going out or maybe there is crap in the lines? This has all been my crash course as far as the inside of the tranny, only engines before this.
One method for getting the PR components out is to leave the retaining ring off; replace the pan and fluid and crank it up. The PR valve and associated parts will quicky hit the bottom of the pan.

A pressure test is, no doubt, the best way to proceed at this point. As long as you haven't seen any debris in the pan until now, you probably don't have anything clogged up.
What kit did you install? The PR valve is a good place to start, but you need to check the TV valve too. These are the two places where a valve body kit install goes wrong.
I checked the TV valve and it is moving freely, I actually took the VB into the house and checked everything slowly and carefully to make sure nothing was out of order.
I spoke to someone at JW Performance, which is where the kit is from (through Poston), who seems to think that I probably have worn bands and is affecting the servo travel. The first time I spoke to him he said to check the TV valve and PR valve. After mentioning to him this time that the 1-2 and 2-3 shifts are the problem, he immediately said the bands. What you guys think?
If so, is it a no no to have one of these trannys freshened up at a tranny shop? Ive heard stories about people winding up with different VBs, etc. Is it a must that I find someone who is a TR tranny expert or should I be able to use a normal tranny shop and just be on them?
I've never used a JW kit for a 200 4R. I don't like anything else they make either. Just my opinion.

Did you have a soft slipping shift BEFORE you put their kit in? If so, then it is possible that the mechanical condition of your transmission is the cause. If you had a decent shift before, and don't now, then either the kit doesn't work, or you've made a mistake in your installation. The condition you describe sounds like lack of pressure rise to me.

No, as a rule you cannot take it to just any shop to have it repaired. You need to find a shop that is intimately familiar with HIGH PERFORMANCE GM overdrive automatics, and you can trust.

If I could see the instructions from the kit and some line pressure readings I could be a little more help.
Good luck,
Thanks everyone for trying to help,
looks like I will need to get that pressure guage. Where would I get one?
As far as the JW kit, you are not the first person here that has said that about them. I didnt know what the brand was when I ordered it and just assumed I would be alright using a kit that a good TR parts distributor would carry. Postons has always took care of me in the past with other items.
The tranny, before the kit, would shift firm. The only problem I had was at WOT it would take too long to shift. Ive heard this complaint on here before. At the track I had better success when manually shifting. (By the way, I can bring up the RPMs and manually shift now, and it will shift smooth, just not firm).
What if I just for the heck of it put some, if not all, of the original springs back in the VB and accumulators to see if the tranny would at least act like it used to. Then the only differences would be the couple of holes I drilled larger in the plate, the hole I plugged in the 1-2 accumulator, and the check balls I left out (unless I put those back in too). Would this be worth doing? Or maybe a portion of it?
Go to a hydraulic supply store and get a zero to five hundred psi guage, an eight foot hose, and a 1/8" male pipe swivel fitting. Total cost should be about $30.

You either have a leak, or something wrong in either the pressure regulator or throttle valve circuits. Take the pressure readings and post the results. Go to a transmission parts store and get an ATSG manual, a Superior 200 4R valve body kit, and a .500" TV boost valve. If you can, reverse the installation of the JW kit. Then, install the Superior kit. If nothing was damaged, that will fix it.
Is the pressure regulator valve the same for all 2004r or is it specific to the BRF trans? I ground off the land on mine and I thought that I took too much material off, so I got another pr valve the "looked" the same and put it in. I didn't touch the land on that one.

The PR valve is not model specific unlike the boost valve assemblies and PR spring.
Okay guys Ive got the Pressure Guage now what?
What readings to look for? In Park, Drive, certain gears? How do I go about testing?
I want to know what condition this BRF is in before I just go ahead and take it out for a rebuild and put the probably temporary KZF in.