HPFP internal seal doesn't look so good...
 

I installed my new internals yesterday, and while cleaning noticed something that has me worried. The 18mm stainless nut assembly has an o-ring on the outside, and there is another rubber seal on the ID that the plunger passes through. It's a double lip seal. The 'top' of the seal looked a bit chewed up for about half its circumference. The ID of both lips looked OK, but I'd really like to replace this seal if anyone knows of a source.

I'm pretty sure you could get it from Mazda?

No dice. They'll gladly sell me the entire HPFP though!

check edge? I remember hearing one of our venders can get these... =)

Ooof. That's no bueno. @EdgeAutosport.com; Help this gentleman out please!

Thanks for the tip guys! I saw on cp-e's site they supposedly install new seals, so I emailed and called them. No response yet...

Chris Connor from cp-e just responded that they will not sell HPFP parts separately. Nice.

Can you take a pick of what you're talking about? I think I have an oring made for the hpfp

Need pics. It might not be as bad as you think. I tore an o-ring when I put the whole pump inside the housing. Wasn't too hard to find a replacement.

I'll try to get a pic tomorrow. It'll be tough to see. It's on the ID, and seals against the small diameter on the shaft/plunger.

IF you can't find a replacement. Buy OEM internals or pump off ebay.

@hnda etr has some of plunger seals. He could sell you some.

OP, Ive gotten some nitrile orings from Advance that have done well by me for close to 10k miles.

The measurements are 1"x 1-3/16 x 3/32

Ninja edit: I might have used these on the spill valve nut thingy, and not the part you are talking about. Either way it cant hurt to try out Advance. Just dont buy EPDM or neoprene.

I wasn't able to find a source before I put things back together, so I just went with it. The sealing surfaces looked fine, it was the outer face that looked iffy. According to silvapain's AP, my fuel pressures are looking good, so I'm not too worried about it at the moment. I'll have my own AP soon, and I'll keep monitoring.

I appreciate the leads. I'm sure I'll get around to replacing that seal some day. I've had enough of working on my car for a while though...

Damn, where were you guys two weeks ago? @Etipp98, is that a close enough deal, or pretty much a direct replacement?

I have used these in about 10 pump with no issues, direct fit.

Yeah i have a shit load of them cuz they only sell in packs of 100 and 50

McMaster-Carr part numbers:
90025k135 = Buna material (Standard OEM)
6540K121 = Viton material (Upgrade over Buna)

They're called Quad-Rings, X-rings or Double-seal O-Rings

I got the rings yesterday, thanks again! Unfortunately the quad ring was apparently not the problem. Add me to the KMD haters group. My internals still look brand new, I am 100% confident that there are no installation issues, and my fuel pressure is still dropping at WOT.

So what now? I bought a set of Autotechs (bonus on timing this with the Black Friday sale, I guess). I have replaced the quad seal and the largest o-ring on the outside of the HPFP assembly. Just to cover all my bases, I'd like to replace the other o-ring: the one on the outside of the 18mm nut assembly. Does anyone know the size or have a McMaster Carr number for that o-ring? I haven't been able to find it searching these forums.

I'd also like to replace the spring if possible. Corksport is including a stiffer spring in their kits when they start selling them, but they won't sell the spring separately. I haven't hit up cp-e yet to see if they will, but I'm not optimistic. Anyone know a source for this spring? At 79,000 miles, my spring may be fatigued.

I think just going for the Autotechs is the best option. I read somewhere that the stiffer spring might wear out the pump lobe prematurely though. Perhaps swap out for the original internals and put a base map on there and see if you get the same dip in FP when going WOT.

Just so you know, CPE is a lost cause, because they don't build their own pumps. APR builds their pumps, so you'd have to contact them if anything.

No problem. Protegegarage.com used to sell upgraded hpfp springs, but I don't see them on their site any more. You might try them to see where they sourced them from.

Thanks for the tip, I just emailed them. Do you have a part number for the large o ring you sent me?

No sorry. That actually came from Brydon at Corksport. He sent a couple to me.

Nice! Do you think Brydon might be willing to help us out with the other o-ring (the mid-sized one that goes on the 18mm nut assy) and maybe even a spring? The random person I got with Corksport customer service was not inclined to help...

Are you talking about the o-ring on the outside of the assembly? You should be able to find a replacement at the hardware store.

I'm talking about the o-ring you see in this picture:

http://rallysportdirect.smugmug.com/...IMG_0417-L.jpg

I'm sure I could find something close, but small dimensional variations and material variations are pretty important in this type of application.

Honestly, any decent car parts car should be able to get that for you. test fit it and see how snug it is. even if it's a little tight, a thicker one will stretch and will perhaps end up even better than the original one on there. My personal experience with those o-rings are that they are a little too loose and get snagged rather easily when pulling that part of the pump out.

Let me check to see the part numbers I got. I replaced mine with PTFE style. They are more superior to regular buna n style o rings. PTFE will hold up to methanol and harsh abrasives better. I wish I could of found one for the inner quattro o ring, but could not. I thought I had a lead on some viton but not yet.

Jason

Awesome, I appreciate you looking into that.

See post #18 above for the McMaster number for the viton quad ring.

If you're talking about a viton quad ring, i've already posted the McMaster-Carr part number for that...

@hnda etr;

Is this the one you have? I must be blind because I did not see it
6540K121
Double seal viton fluoroelastomer

Cross reference over to Grainger as:
3CRT2 (pack of 5) for $10.63

Also found them at:
ww.theoringstore.com for .36 cents each for 1-24, 0.18 cents for 25-99 (that is the QR NBR (nitrile rubber).

These are in inner small o ring that the piston shaft makes contact with. Let me measure and verify the outer o ring that is on the 18MM hat.

Jason

In the below post # 18

I finally got my Autotechs about two weeks ago, and all is well. Pressure doesn't drop below 1750 at WOT. New quad ring, outer o-ring, and I scored a brand new spring from Corksport. HPFP ought to be good for a long time now.

@hnda etr, thanks again.

So this is the measurement^^^^^ for the the o ring on the threaded part of the internals?? Also whats the specs on the o ring between the hpfp and cylinder head

Holy necrothread. I can't verify the first question. Answer to the second is here

well i picked up the outer o ring from mazda $12. this is the one that seals the hpfp to the cylinder head but i am still looking for the specs for the one on the threaded assembly when you install the internals. i saw what others had posted but the id just seems so small. isnt the threaded assembly itself about 19 - 20 mm in diameter??

I replaced mine (accidentally got break cleaner on it, and it got messed up)... Just went down to NAPA and got one that was close - cost like $1 or something. It's been working fine for 50k miles with 50/50 e85 mix

Just tell them its for use in the fuel system so they get out the right box for you.

brah, im new here lol, how do i sub to this thread?
nvm! got it!