THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

Hello everyone! I have been lurking and learning here for a while!
I have a pinzgauer 710m 1974. My problem is I have a bad oil leak , the weird part is it looks like it’s coming from the back bolt near the fuel pump? I put new seals in the oil cooler and cleaned it last summer . I took the rear top tin off to see if it was a pushrod tube and everything was dry. Any ideas as to how or why that would leak and how to fix it?
Thanks!

Oil leaks can be very sneaky, would help to see a PIX of the offending area.

the rear nut holding the tin .

This rear nut is where oil was bubbling out.

right were my finger points

Hmmm, that's mighty odd.

All the M6 studs that hold tin are in blind holes so Oil can't just leak from the block.

Couple of thoughts, first would be the Lifter housing where the push rod tubes
terminate to, possibly a failed gasket. But you would also see oil leaking down
below from the bottom cylinder tin.

Another possible is the Fuel pump, but I presume that would have jumped out
as the source immediately.

From my own experiences chasing phantom oil leaks can be very sneaky.
Often the best first thing is to clean clean clean than observe -- but things look
mighty clean already, even around the Cam gear housing !

About how much Oil are you leaking say per 1,000 miles?

I lost a quart in 20 miles. I’m not sure if I can post video on this site , but I took a short video and oil was literally bubbling out of that rear stud. Oil was everywhere. But like I said , I took the rear carb off and the rear upper tin and everything is as dry as a bone.

Well maybe worth pulling the fuel pump. And inspecting around there. Though
it almost seems like oil would have to go uphill for that to be the source. Odd.

Well , I took a bunch of tin off to get a better look at things and decided the oil has to be coming from the fuel pump area. I then took the fuel pump off and cleaned the gaskets and used gasket maker and the leak seems to have stopped. I’m not sure how the oil migrated over there but it has to be where it came from.

Well hopefully that holds up which would be very good news !

ron

Just jumping on the forum after being away for a bit. Came across this post. I had the exact same thing happen to me during a long trip last August. Lost 2 qts of oil in 400 miles. Traced the leak to the fuel pump base. It vibrated lose during the trip. Fortunately for me I tightened up the base bolts & the leak stopped. Added oil & all seems OK now. Cleaned up the residual oil as best I could. Still get a drip every now & then but seems to have fixed the problem. Although not the main problem the experience caused me to get a spare pump & gaskets for peace of mind. Hope your leak is also resolved.

Best,
BobV

Hey guys, new here, Canadian based in Switzerland.
Juts bought a 710M from Swiss army recently.
I knew I had a bit of oil leak under the starter,
so after reading this post, I opened up the hood and checked the fuel pump.
Indeed it's pretty gunky in there at the base.
So I sprayed some WD40 and cleaned-up as much as I could.
Started the engine and ran for a while, could not see anything suspicious.
But I'll monitor it for a while.
If I see oil coming back, as a next step, should I juts tighten up the nuts ?
Or should I already change the gasket ?
That would be #27 on this page ?
https://www.puch.at/en/products%20&%20s ... el-system/
Seems there are 2
Is it a sensitive task when you pull out the fuel pump ? I've got the repair manual, seems like straightforward.
Anything I should pay attention to ?
thanks

Yes, there are a pair of gaskets (same) on each side of the pushrod "interposer".
It would not hurt to check to see if the two nuts have loosened, giving them a
bit of a tightening. Also thoroughly clean the area to confirm it's leaking. If so,
it's pretty quick and easy to replace the gaskets.

P.S. if you are still seeing oil leaking near the starter motor but no evidence it's
coming from the fuel pump mount, then check the area around the oil cooler.

So, removed the top of the fuel pump yesterday to change the gaskets,
i realised the base of the fuel pump is cracked, not sure how can this happen,
so i'm looking to order a new one, i did not pull it out by fear of worsening the problem,
put some grease inside the crack hoping it will last a few more days,