HPFP O-rings

Thanks for the reply, I removed the pump again today. The spring side smelt like it was covered with fuel. The metric X-ring that I had fitted has a larger ID than the shaft of the piston that is meant to seal against and is larger than the original X-ring, but once fitted into the housing it seems to seal OK, well I thought it was sealing OK. I have now sourced and fitted a SAE -011 X-ring. Ill see how this goes, otherwise I will refit the original X-ring.
 
The Xring that is listed in the OP worked great for me. I see that you are in AU, so any local supplier that can match those specs should be ok.

I used a little glaze of motor oil to assemble everything back up, and the Xring gave me a slight fight when reinstalling the piston shaft. Be very careful with the Xring because if you didnt lube it enough, it is possible that the ring could have torn or twisted on itself.

Also check the outer screw seal. IIRC that one fit looser until you screwed the internal assembly back into the housing, so there is a chance of that one binding or tearing.
 
Yeh the outer seal worried me, so I refitted the original one, and the metric x-ring looked ok and seemed un-damaged.
I’m going to start it up this morning, see how it goes.
 
Robski said:
Ok it’s been almost a month of driving my MPS and all seems ok, there is still a hint of fuel smell but the oil level has remained the same.
Thanks for the advise.
Click to expand...


Which x ring did you end up using? Mine tore while installing my new internals. I want to purchase the Mc Master Carr x ring posted in the link "1200N156"
 
X-rings require a little finesse when installing so they don't get twisted or torn, unlike round profile o-rings that are a bit more forgiving. If you have a pick set (HF or other) carefully use the pick to get the first section of the x-ring seated. Use lube and take your time.
 
Hi, sorry I haven't been on the forum for a while, I removed the metric Buna-N 1200N156 x-ring which was leaking and fitted the SAE -011 X-ring, seems OK so far. Oil level hasn't changed, since 27 Jun, driven almost every day since.
I should add, a few months ago, the car developed a cyl 3 misfire. Coils OK, Plugs OK. Found injector 3 faulty, replaced number 3 and had the rest cleaned. I cleaned the very black and oily manifold and valves while I had access, also cleaned out the EGR and left that disconnected, replaced the PCV and added a Damon OCC.
The car now starts and runs so smooth, doesn't blow smoke anymore and doesn't run rich, no more stinging eyes.
The only problem now is with the lack of engine fumes, I can smell the oil seeping out of the transfer case.
 
Update from McMastercarr:

X-Profile Oil-Resistant Buna-N O-Ring, 2 mm Wide, 8 mm ID, Part number: 1200N156

This product is no longer available.

We suggest: 9262K169. Cross section shape: round vs. x-profile.

@Robski - Which one did you use? Does anyone have a good source for these, outside of a kit, perhaps a Viton one instead of Buna-N?

The only downside of an o-ring vs an x-profile ring, is that the latter has two slightly more rigid sealing surfaces, vs. just one on the o-ring. Perhaps it will last half as long, which at 50k miles is still a while.
 
Last edited:
The other day my spill valve was leaking fuel and it turned out to be an internal oring. I tried to measure (maybe 1.5x22) but ended up taking the old inner o'ring to Hecht Rubber and they sold me few gaskets but I forgot to ask what size was it. If someone knows spill valve inner oring size, it would be good to know.
 
You must log in or register to reply here.
Back
Top