throttle body tps boost leak

Discuss the RB20, RB25 and RB26 series engines.
jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

I decided to do a leak check on everything after a very nasty cruise. Hit some back road with some of the guys. Lots of uneven surfaces, not to my liking. Ended up blowing off a couple pipes and dented and cracked my down pipe pretty good. Anyway, I found out my throttle body is leaking pretty good out of the tps shaft. Is there a seal replacement for it or is it time for a new one? I put an o-ring in between the tps and the throttle body. It has helped but, didn't stop the leak completely.

http://www.youtube.com/watch?v....html

I'm the green s14 at the start of the video.
Modified by jdmser at 3:26 AM 7/14/2008


Sil240
Posts: 2973
Joined: Mon Apr 28, 2003 5:26 pm
Car: Nissan S13 "The One Cam Wonder"

Post

Bro go to Autozone and tell them you need a seal.Bring your Tbody with you.

They might say that they don't have it, but the have a box of random seals. Different sizes.

If not go ahead and put a dab of caulk on it.Just make sure you can open up the throttle.

Yellow4g63
Posts: 3718
Joined: Mon Jan 20, 2003 6:07 pm
Car: 95 Nissan RB20 240SX RB20
91 Nissan NX2000 VE power
95 Nissan 240SX Stock
Contact:

Post

jdmser wrote:I decided to do a leak check on everything after a very nasty cruise. Hit some back road with some of the guys. Lots of uneven surfaces, not to my liking. Ended up blowing off a couple pipes and dented and cracked my down pipe pretty good. Anyway, I found out my throttle body is leaking pretty good out of the tps shaft. Is there a seal replacement for it or is it time for a new one? I put an o-ring in between the tps and the throttle body. It has helped but, didn't stop the leak completely.

http://www.youtube.com/watch?v....html

I'm the green s14 at the start of the video.

Modified by jdmser at 7:29 PM 7/13/2008
If you need another RB20 throttle body let me know I have a 2 extra ones. 1 came off my motor so I know that dosen't leak and the other is off the Rdtop RB20.

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

Thanks for the offer but, if I can't fix this one for cheap I'm prolly gonna go with something a little bigger. Maybe an 80mm.

User avatar
mello88
Posts: 611
Joined: Tue Jul 27, 2004 6:37 am
Car: s13

Post

FYI... I had the exact same leak from my TPS shaft. Would leak at over 5psi. I contacted MaxBore.com about boring & rebuilding the TB, he told me that he's tried to rebuild these in the past and it was impossible due to how the TB shaft seal is assembled. I've never taken it apart myself to see if this is true or not... I just bought another used 20 TB. GL

User avatar
Coolwhip
Vendor
Posts: 3138
Joined: Fri Feb 06, 2004 7:29 am
Car: RB26 Raw Brokerage War Machine
Location: Orlando, FL
Contact:

Post

You're better off with replacing you're throttle body.

User avatar
rudedrift
Posts: 22
Joined: Sat Jan 14, 2006 8:58 pm
Car: 240sx
Contact:

Post

man, i may have the same leak, i've been chasing ghosts for a month now.these problems on rb25 also?

User avatar
Coolwhip
Vendor
Posts: 3138
Joined: Fri Feb 06, 2004 7:29 am
Car: RB26 Raw Brokerage War Machine
Location: Orlando, FL
Contact:

Post

the problem will exist on any throttle body of the same style and enough age.

The RB26 guys find themselves blowing their's when pushing alot of boost and just imagin tracking down that damn leak with ITB and a good handful of seals which nissan doesn't sell. haha, single tb time for most.

I have a RB20 TB here and I believe I should have a RB25 as well in a box somewhere.

User avatar
lilskyline240
Posts: 1887
Joined: Fri Oct 14, 2005 9:55 am
Car: 90 240sx w/ rb30det

Post

i had the same leak but on a q45 throttle body. I tried everything to fix it but after talkin to lots of ppl at dealerships and shops they all suggested to just get a new TB.

i have a spare stock rb25 throttle body if your interested

Sil240
Posts: 2973
Joined: Mon Apr 28, 2003 5:26 pm
Car: Nissan S13 "The One Cam Wonder"

Post

WOW RJ's alive!!!!!What up it's Brian from [email protected]

Umm.... I dunno about changing your whole throttle body because 1 seal is bad.It had to be put together, soo you can take it apart and put another seal in there.

Has anyone tried to pull the Tbody apart??


240z4u
Posts: 2071
Joined: Mon Feb 21, 2005 4:47 am
Car: '95 Nissan 240SX

Post

Sil240 wrote:WOW RJ's alive!!!!!What up it's Brian from [email protected]

Umm.... I dunno about changing your whole throttle body because 1 seal is bad.It had to be put together, soo you can take it apart and put another seal in there.

Has anyone tried to pull the Tbody apart??
You can't get the seal. Different TB is cheap. Totally not worth the hassle.

Oh, and its not one seal, its the ONLY seal.

Sil240
Posts: 2973
Joined: Mon Apr 28, 2003 5:26 pm
Car: Nissan S13 "The One Cam Wonder"

Post

But have you taken the TBODY apart to get the dimensions of the seal?????

In Jamaica, you fix shyt.In the US you buy new shyt.

I'm sure that thing can be fixed.When you get your new Tbody take apart the old one.Post a couple of pics, I'm sure it'll help someone.

User avatar
lilskyline240
Posts: 1887
Joined: Fri Oct 14, 2005 9:55 am
Car: 90 240sx w/ rb30det

Post

here ill send u my leaky q45 TB and u can tear it apart then post on here that u cant fix it. I tore mine apart. Trust me, its not fixable

User avatar
rudedrift
Posts: 22
Joined: Sat Jan 14, 2006 8:58 pm
Car: 240sx
Contact:

Post

that's what i do, just fix ****. spend that money on new other ****.

what up Brian?

Sil240
Posts: 2973
Joined: Mon Apr 28, 2003 5:26 pm
Car: Nissan S13 "The One Cam Wonder"

Post

It's not fixable because you can't get the seal???

Is it some odd shaped seal???

If you get the specs on the seal I could probably find one.

Have you ever check Mcmaster Carr or Grainger or Lawson?They have lots of random harware and seals etc....

User avatar
mello88
Posts: 611
Joined: Tue Jul 27, 2004 6:37 am
Car: s13

Post

I was told, "Sorry I don't have parts to repair your TB. If I remember correctly, the shaft is pressed in so I am not sure if there is a seal in there to begin with."

Maybe I'll pull my leaking TB apart and see how it seals.

240z4u
Posts: 2071
Joined: Mon Feb 21, 2005 4:47 am
Car: '95 Nissan 240SX

Post

mello88 wrote:I was told, "Sorry I don't have parts to repair your TB. If I remember correctly, the shaft is pressed in so I am not sure if there is a seal in there to begin with."

Maybe I'll pull my leaking TB apart and see how it seals.
If the shaft was pressed in, it wouldn't turn.

This was also a big problem with SU carbs from the early zcars. Ztherapy sold carbs that were totally rebuilt with teeny ball bearings pressed in. I had a set, very nice and trick.

Evan

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

I fixed the leak. I had a o-ring assortment laying around that I got at Home Depot to fix a leaky faucet. It had one that fit perfectly around the throttle shaft and another that fit the hub on the back side of the tps. I tightened the tps back up and it held 25psi from my air compressor.

Yellow4g63
Posts: 3718
Joined: Mon Jan 20, 2003 6:07 pm
Car: 95 Nissan RB20 240SX RB20
91 Nissan NX2000 VE power
95 Nissan 240SX Stock
Contact:

Post

jdmser wrote:I fixed the leak. I had a o-ring assortment laying around that I got at Home Depot to fix a leaky faucet. It had one that fit perfectly around the throttle shaft and another that fit the hub on the back side of the tps. I tightened the tps back up and it held 25psi from my air compressor.
Does the car feel better or the same since u fixed that boost leak?

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

I'm still waiting on the downpipe to come back from being welded. I let you know as soon as its back together.

240z4u
Posts: 2071
Joined: Mon Feb 21, 2005 4:47 am
Car: '95 Nissan 240SX

Post

jdmser wrote:I fixed the leak. I had a o-ring assortment laying around that I got at Home Depot to fix a leaky faucet. It had one that fit perfectly around the throttle shaft and another that fit the hub on the back side of the tps. I tightened the tps back up and it held 25psi from my air compressor.
Nothing better than finding a fix like that, nice job.

Evan

Sil240
Posts: 2973
Joined: Mon Apr 28, 2003 5:26 pm
Car: Nissan S13 "The One Cam Wonder"

Post

See i knew there would be a easy and CHEAP fix.


jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

FIX DID NOT WORK--I was replacing the hoses to the IAC today and had to push the throttle out of the way to get to some hose clamps. When I let it go it was extremely slow to close. I used a little dab of bearing grease on a q-tip to lube the o-ring but, that only work for a few snaps of the throttle.

User avatar
rudedrift
Posts: 22
Joined: Sat Jan 14, 2006 8:58 pm
Car: 240sx
Contact:

Post

what if you changed up "how" you used your o rings?is there a possibility at all of correcting this problem?

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

I'm going to try and use a thinner o-ring and see what happens. The only problem is I think the pressure from squishing the larger o-ring between the tps and the throttle body is sealing the leak as well as delaying the throttle from closings.

User avatar
Kansei240sx
Posts: 1356
Joined: Mon Nov 01, 2004 10:17 am
Car: S13 - RB25 Circuit car
71 240z - street/track day car
AE86 - Daily Drizzle/track day car
Z31t - Paper weight/street car
Contact:

Post

If you lubricate that o-ring dont use grease, use something like KY that wont make the o-ring swell up.

crccustoms
Posts: 14
Joined: Mon Mar 03, 2008 3:49 am

Post

id imagine you could use rtv sealant combined with an o-ring to get it to seal under normal pressures, but if your using higher boost levels your probably best off getting a bigger bore throttle body or i do believe the rb25 throttle body fits the 20 and that would be an upgrade and probably a little cheaper, i also suggest using petroleum jelly every time you use an o-ring, and when you reassemble it coat it liberally with rtv and then just wipe off any of the excess, good luck and i hope that i could help!

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

I messed around with trying to get the throttle body to seal with different size o-ring and had no luck. Every way I tried that made it seal also effected throttle return. Can anyone confirm that the RB25 throttle body will bolt on to the RB20 manifold and is an upgrade or reccomend an aftermarket throttle body that is a straight bolt on to the stock manifold?

jdmser
Posts: 716
Joined: Thu Oct 09, 2003 1:31 am
Car: duh

Post

Picked up a throttle body from a sohc ka24 yesterday. It bolt to the rb20 manifold and is the same size but, the throttle plate opens counter clockwise. That would we fine except that it would give a tsp signal starting at 5v and ending at 0.5v instead of the other way around. I tried to swap the throttle plates and springs to make it open clockwise but, the throttle plate for the rb20 is thicker that the ka's and wouldn't fit. I hate to do it but, I think I'm going to get one of the universal 80mm off of ebay unless somebody has heard they're no good.

auy_tong2
Posts: 9
Joined: Wed Nov 11, 2009 2:34 pm
Car: R33 GTR Nissan Skyline

Post

is this a RB26 engine? i also have leak in throttle shaft/body....


Return to “RB20DET / RB25DET / RB26DETT Forum”