Brake Booster Check Valve

[Scrymerr]

Factory brake booster line on a 2g is 11/32. I am looking for a nice metal check valve that will be more resiliant than the factory valve and either fit inline, or thread into the manifold. Something similar to the MKIV Supra would be cool. There were a few threads mentioning a stronger valve, but no specifics.

Dan

 

[turbosax2]

Search for "check valve" at mcmastercarr.com - you can find just about any size check valve you need there.

How about using a Brass Spring-Loaded Piston Check Valve 3/8" NPT Male X 3/8" NPT Male, Viton Seat (#7768K57) with two 3/8" hose barbs (5346K55) <-- only comes in packs of ten.

Or if you know the size of the threading on the intake manifold for the nipple, you can get a check valve to thread right into the manifold with a hose barb on the other side.

What do the Supra's use?

 

[asiahispanico]

now with my understanding a check valve works like the pcv valve right? well dont go to the dealership for this part i did and i paid 4 dollars for a regular fitting, i asked for brake booster CHECK valve and they gave me a regular fitting. With that check valve from mcmaster-carr its fits inline correct?

 

[turbosax2]

You're correct, a pcv valve is a type of check valve. The brake booster check valve allows the booster to see vacuum, but not boost, by only allowing flow from the booster to the intake manifold.

The factory check valve is physically inside the booster line so you can not buy it separately from the dealer. To get a new one, you would have to buy the whole booster line which comes with the valve inside (part #MB895885, about $11 from the dealer).

If you set up the check valve like I explained above it will be able to be used with the factory line. You will want to cut the line up to remove the factory check valve though. I wouldn't really consider this an "upgrade" though as I don't hear of these check valves failing often. If I were you I would just buy a new oem booster line.

 

[Scrymerr]

Thanks for the reply Turbosax2, that was perfect! I can highly recommend mcmaster as well. I ordered a brass check valve with a viton seat for $13 at 5:00pm on Tuesday and got it Wednesday afternoon (helps that they are in CA). I installed the valve today, and it seems great: no leakage when boost leak testing, and flawless operation for boost to brake situations.

I would bet than many people have a failing/failed valve but do not know because they do not boost leak test. After looking at the stock valve, it does not surprise me that it would fail with increased boost fairly quickly.

 

[bmoha2]

This the third time my brake booster check valve failed. I first replaced it with the stock brake booster vacuum hose with it's built in one way check valve that is facing in the correct direction. It was an immediate failure. As soon as the Talon sees over 17psi of boost it blows open, pressurizes the brake booster and in effect applies the brakes. I replaced it with a much higher quality brass one way check valve that was supposed to be impervious to oil and high temps and should have been good to 160psi. It worked great for about five months and then stopped working. I rerouted the pcv valve out into a catch can instead of into the intake hoping that maybe I would eliminate some crud that was affecting the performance of it. I got a new high quality check valve but less than two days later it is acting up. The stats on the stock one way check valve are amazingly low as far as back pressure that it is able to withstand. I have the Talon running so damn good other than this brake booster check valve boost leak! It's very frustrating! I'm going to look into the offerings from mcmaster. I have deleted the egr system with the egr blockoff plate and everything else has been taken out.

 

[bmoha2]

It looks like I got a bad new check valve from mcmastercarr. The valve I got from them seems to want to stick partially open and only open or fully close when doing hi boost or total off throttle deceleration. It's still pumping up and dragging pads on rotors. The rotors, calipers, brakes pads and ss lines are all brand new with thoroughly bled 5.1 brake fluid. I'm going to have to call them and get a new check valve sent. When I was playing with the valve before installing it. I couldn't get smooth trouble free performance out of it. Seems like there was a bit of stiction preventing it from working exactly as intended.