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rcooled
Samba Member
Joined: September 20, 2008
Posts: 2506
Location: Santa Cruz, CA
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 Posted: Tue Aug 21, 2018 5:44 pm Post subject: Re: Oil pump to case leak |
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| FL-Frank wrote: |
| ...oil is running down the right side of the pump to case seam...this is frustrating! |
Here's something to check. When installing the pump, if one of the cam gear bolts is near the 6-o'clock position, you may have an interference problem between it and the pump. The issue is with the lower boss on the rear side of the pump that holds the shaft for the driven gear. If one of the cam bolts is in just the right spot (6-o'clock) when installing the pump, that boss will touch the bolt head and not allow the pump body to seal properly against the engine case. Using fasteners with a low-profile head, like button-head socket bolts, to attach the cam gear will prevent this from happening.
I once had a pump-to-case leak that drove me nuts and that turned out to be the cause. The cam gear was already mounted with standard hex bolts, so I had .030" milled off the pump boss to provide some extra clearance and the pump was leak-free from that point on.
I always apply a thin coat of Permatex Ultra-Black Gasket Maker to both sides of the pump-to-case gasket for good measure too.
_________________
'63 Ragtop (current)
'65 Ghia coupe (totaled)
'67 Ghia convertible (current)
'69.5 Ghia convertible and
'62, '63, '65, '69 Bugs (all long gone) |
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FL-Frank
Samba Member
Joined: August 08, 2015
Posts: 823
Location: Jupiter, Florida
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| Posted: Tue Aug 21, 2018 6:27 pm Post subject: Re: Oil pump to case leak |
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| rcooled wrote: |
| FL-Frank wrote: |
| ...oil is running down the right side of the pump to case seam...this is frustrating! |
Here's something to check. When installing the pump, if one of the cam gear bolts is near the 6-o'clock position, you may have an interference problem between it and the pump. The issue is with the lower boss on the rear side of the pump that holds the shaft for the driven gear. If one of the cam bolts is in just the right spot (6-o'clock) when installing the pump, that boss will touch the bolt head and not allow the pump body to seal properly against the engine case. Using fasteners with a low-profile head, like button-head socket bolts, to attach the cam gear will prevent this from happening.
I once had a pump-to-case leak that drove me nuts and that turned out to be the cause. The cam gear was already mounted with standard hex bolts, so I had .030" milled off the pump boss to provide some extra clearance and the pump was leak-free from that point on.
I always apply a thin coat of Permatex Ultra-Black Gasket Maker to both sides of the pump-to-case gasket for good measure too. |
Here’s my cam gear. What do you think?
_________________
“Tinker Toy” 1967 Savannah Beige Beetle Sedan...........Mostly Original Survivor
“Fritz” 1964 Gulf Blue Karmann Ghia Coupe...Complete Pan-Off Restoration SOLD |
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rcooled
Samba Member
Joined: September 20, 2008
Posts: 2506
Location: Santa Cruz, CA
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| Posted: Tue Aug 21, 2018 6:52 pm Post subject: Re: Oil pump to case leak |
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| FL-Frank wrote: |
| Here’s my cam gear. What do you think? |
Check the back of the oil pump. You might be able to see some witness marks on the face of that boss if there was any interference.
The position of the bolts in your photo would be correct to cause the problem I described. The cam bolts in my motor showed no signs of wear and I heard nothing unusual when it ran. It was some scuff marks on the boss that tipped me off to the cause of my leak.
_________________
'63 Ragtop (current)
'65 Ghia coupe (totaled)
'67 Ghia convertible (current)
'69.5 Ghia convertible and
'62, '63, '65, '69 Bugs (all long gone) |
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FL-Frank
Samba Member
Joined: August 08, 2015
Posts: 823
Location: Jupiter, Florida
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| Posted: Thu Aug 23, 2018 11:30 am Post subject: Re: Oil pump to case leak |
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Taking my time to measure everything with the digital calipers this go ‘round before I reassemble anything.
And, I think I may have a problem with oil hole sizing compatibility....
Case oil hole diameters (40 HP single relief case)
Left side. 7.95mm
Right side. 9.90mm
26mm pump that was on the engine hole diameters
Left side. 11.89mm
Right side. 9.58mm
New 21mm pump hole diameters
Left side. 13.97mm
Right side. 11.95mm
New 26mm pump hole diameters
Left side. 12.39mm
Right side. 10.29mm
The new 21mm pump is Schadek brand with 8mm stud holes. The 26mm pump that was on the engine and also the new 26mm pumps are also Schadek, with 6mm stud holes.
I read in Fishers “How to Hot Rod VW Engines” in the oil pump blueprinting section the following...”the 70-71 pumps cannot be used in the pre-1970 cases because the larger holes in the 70-71 pumps do not match the small passages in the early cases and it may be impossible to get a prime or suitable oil pressure due to leakage.”
So, I’m wondering now if the oil pump leak issues I’ve been experiencing are being caused by a pump whose oil holes are not compatible with the cases small oil holes???
Meanwhile, I’ve also sourced an NOS 21mm pump with 6mm stud holes that should arrive early next week. Curious to see what size oil holes it has.
Update to follow.
_________________
“Tinker Toy” 1967 Savannah Beige Beetle Sedan...........Mostly Original Survivor
“Fritz” 1964 Gulf Blue Karmann Ghia Coupe...Complete Pan-Off Restoration SOLD |
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FL-Frank
Samba Member
Joined: August 08, 2015
Posts: 823
Location: Jupiter, Florida
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| Posted: Sat Aug 25, 2018 3:29 pm Post subject: Re: Oil pump to case leak |
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I checked with the fellow that built the motor years ago, and he advised me to stay with a 26mm geared pump vs. dropping down to a 21mm pump. He also told me not to worry about the pumps holes be larger than the holes in the case. Finally, he recommended that I seal the pump to the case with Loctite 518 and no gasket.
So, I blueprinted the new 26mm geared Schadek pump I have, and then followed the builders advice for sealing the pump to the case. In order to avoid contaminating the pumps pressure relief groove with sealant, I decided to use the thin gasket soaked in motor oil for the seal between the cover and pump.
I finished it off with 4 new sealing nuts torqued to spec.
After reassembing everything...came the moment of truth. I started it and let it idle for 5 minutes while I looked around underneath for any signs of leaks. Dry! I revved it several times and went back under to inspect. Still dry! I then shut it off, dropped it to the floor, and put a drip pan under it. 2 hours later, the pump and cover area still looks dry, and nothing on the drip pan!
I hope its still dry with no drips on the pan when I check it again in the morning, fingers crossed!
_________________
“Tinker Toy” 1967 Savannah Beige Beetle Sedan...........Mostly Original Survivor
“Fritz” 1964 Gulf Blue Karmann Ghia Coupe...Complete Pan-Off Restoration SOLD |
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calvinater
Samba Member
Joined: September 06, 2014
Posts: 3330
Location: 802 The Pointless Forrest
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| Posted: Sat Aug 25, 2018 3:42 pm Post subject: Re: Oil pump to case leak |
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Yay! , love it when things go right
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"Albatross"! |
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FL-Frank
Samba Member
Joined: August 08, 2015
Posts: 823
Location: Jupiter, Florida
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| Posted: Sun Aug 26, 2018 4:15 am Post subject: Re: Oil pump to case leak |
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12 hours later...and everything is bone dry underneath with nothing on the drip pan 
_________________
“Tinker Toy” 1967 Savannah Beige Beetle Sedan...........Mostly Original Survivor
“Fritz” 1964 Gulf Blue Karmann Ghia Coupe...Complete Pan-Off Restoration SOLD |
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Cusser
Samba Member
Joined: October 02, 2006
Posts: 31378
Location: Hot Arizona
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| Posted: Sun Aug 26, 2018 6:48 am Post subject: Re: Oil pump to case leak |
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| FL-Frank wrote: |
| 12 hours later...and everything is bone dry underneath with nothing on the drip pan |
Time to take it on a ride and then do a look-see.
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297 |
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FL-Frank
Samba Member
Joined: August 08, 2015
Posts: 823
Location: Jupiter, Florida
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| Posted: Sun Aug 26, 2018 7:04 am Post subject: Re: Oil pump to case leak |
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Went for a 10 mile cruise this morning, (up to 4,000 rpm). Upon return to the garage everything is dry down below and no drips on the pan 60 minutes after return and shut down
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“Tinker Toy” 1967 Savannah Beige Beetle Sedan...........Mostly Original Survivor
“Fritz” 1964 Gulf Blue Karmann Ghia Coupe...Complete Pan-Off Restoration SOLD |
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