RB26DETT Throttle Seals

[XSDAILO]

EDITED WITH UPDATED LINK 3/18/2009

I noticed that there is quite a bit of engine rebuilding going on with you GTRC guys. I thought you all might like to know about our throttle shaft seals. Everybody seems to overlook them during a rebuild, but we find that most high mileage RB26DETTs, especially BNR32 engines, have leaky throttle seals. Here's the cure:

XS ENGINEERING RB26DETT THROTTLE SHAFT SEALS

You will not find these seals in Japan or anywhere else in the world. They are designed by XS and made in the USA.

[lucky_cefiro]

Thanks guys, I personaly know of a few members who have this issue.

great work as always.

[vassago12]

Wow, very nice work. This could be the fix I am looking for to handle my high idle issue. As a side note do you guys know anything of the factory coating inside the throttle bodies to aid them in sealing at idle? I cleaned my throttle bodies up and was led to believe I likely removed this seal in the process. Hopefully thats not the case and these will solve my problem.

[XSDAILO]

Wow, very nice work. This could be the fix I am looking for to handle my high idle issue. As a side note do you guys know anything of the factory coating inside the throttle bodies to aid them in sealing at idle? I cleaned my throttle bodies up and was led to believe I likely removed this seal in the process. Hopefully thats not the case and these will solve my problem.

Thanks guys.

The factory "sealant" between the plates and throttle bores does aid in sealing the throttles, but your idle speed motor if properly functioning (many BNR32 AAC valves are clogged or gummy inside) should have the ability to run at a low enough pulsewidth to drop your idle speed. When you do take the assembly apart to install these seals, it would be a good idea to probably put a thin coating of the "sealant" back on the edge of the throttle plates. While you're at it you can disassemble, clean, and reassemble your AAC valve to ensure everything is operating properly. I have to check with my machinist and see what he uses as the sealant. I know that it's a hardening type of liquid and not a silicone type of sealant.

[vassago12]

That would be great Eric. I would be very interested to know what type of sealant to use as mine is long gone. My AAC valve is spotless so all thats left to do is reseal those throttle bodies and replace those shaft seals and I should be set . Thanks for all the help.

[XSDAILO]

To seal thottle plates, we use a thin coat of Testor's enamel grey colored paint. The key word here is THIN. After applying, leave the paint to dry for 2.5-3 hours. After drying, you can open the throttle. Apparently, we got this from the boys at RC Engineering who have been using Testor's enamel for the last 20 years on throttle plates.

Testor's is a brand of model paints so you can pick it up at a hobby store.

[vassago12]

Testor's paint eh? Never would have guessed! Thank you for the info! I have been searching for months trying to find something to re-seal those throttle plates.

Scott

[XSDAILO]

You can even buy whatever color suits your mood. How cool is that? Just make sure you use the enamel - the plain enamel and not the other 10 types of enamel that Testor's offers. You can buy them as small as 1/4oz bottles I believe.

[R32GT-R]

do you apply this with the throttle plates in place, or do you remove and apply to the thin edge of butterflys?

[XSDAILO]

You apply this with the throttles at full close. A THIN layer only.

[noodl35]

I'm having the same issue as well. I just cleaned my itb's not knowing that there was sealant already applied by the factory in the bores. So you want us to put that enamel paint while the plates are closed correct? I always figured you would need to put the paint on the complete surface of the bore with the plates are out so you could get a perfect seal b/w the plate and bore surface. Can you explain the reasoning while doing this process with the plate intact? Thanks

[XSDAILO]

If you have the throttle plates out and you apply the enamel, #1-you will not know exactly where the plate rests within the bore and #2-there will not be a perfect seal because the enamel cannot dry against both the plate and the bore. You would have to attempt to build up several layers of enamel on the bore only and even then the plate may no longer close if you have layers of enamel goop on the bore.

Trust me: apply the enamel with the throttle closed in the bore and the enamel will dry to create a good enough seal for your AAC solenoid to work correctly. We've done it this way for years with absolutely no problems.

The reason why it's critical that you apply only a thin layer is because if you apply a thick layer or many layers, the enamel will not dry throughout and will tend to get crusty. Over time, the thick layer of enamel goop will break apart and enter your engine AND no longer seal the throttle plate.

[noodl35]

Thanks for the information. Also I saw those throttle body seals. My r33 motor only has like 22k miles on it. Should I worry about the stock seals? I have been spray some brake cleaner on the ITBs to clean the outside and inside. Should I worry? Also is there a way to test to see if the seals are leaking or bad? Thanks.

[XSDAILO]

If your engine really has 22k then you're probably fine although the engine could be 12 years old by now (I don't know the year of your car obviously). You should have been able to get an approximation of the mileage if you cleaned the throttles yourself. Super oily/greasy/blackish = old and cleaner = newer. You'll have to pressure test the charge system to know if they're leaking or not. Unfortunately most people find out their seals are bad when the seal either pops out or if the idle is all jacked up.

On the other hand, if you have the throttles out replacing the seals is definitely cheap insurance considering how much time it takes to pull apart the intake manifold assembly again. Now since the Canadian dollar is 1 to 1, it's not expensive either.

[noodl35]

alright Eric, I went ahead and bought the seals for insurance. Now what kind of enamel should I purchase? Testor right? What specific model do you suggest? Thanks.

-David