Inline Conversion - Oil Priming Issues

[vanagonjr]

[?Waldo?]

That pump has the correct pickup tube, but the shaft of the pump is different from the ABA pump and will not work on your engine.

[denwood]

Van cafe doesn't list the 82 vanagon diesel oil pump but they did source it for me. I prefer to deal with them. I also sourced a new A3 36mm pump from Techtonics. Both parts were Febi, and both had end play in the .006" range new. Knowing that the oil pump is a very high wear part (sees oil before the filter), and this clearance will only increase, it makes sense to bring this clearance down to .002" or so. The oil pressure results after speak for themselves I think. . I'll post pics of the parts..

You're using the A3 pump bottom end bolted to the 82 vanagon diesel pickup tube assembly to create a hybrid pump. As Andrew points out, the leftover parts create a diesel oil pump that could be used for an upright diesel conversion (using TDI pan)
_________________
Cheers,
Dennis Wood
The Grape

[Mike Pratola]

I had a similar problem with my I4 aba/1.8 conversion. Pump gear backlash and axial play all checked out within spec. I took the pump to my local machine shop/engine builder who immediatly made the call of a sticking pressure reliefe valve. We took the valve apart, cleaned the bore with a small hone and them wrapped the hone with 1000 grit wet/dry emery paper and polished it and the piston until the piston would slide freely in the bore just by tilting the pick up arm. We weren't having any success re-staking the relef spring end cap so we drilled a hole and pinned it with a cotter pin. Buttoned it all back up and using 15/40 the oil light instantly goes out upon start up, when hot shows about 25# at idle and 50# + at around 3 grand. Hope this helps.
_________________
67 Bug, currently in hibernation
78 Westy, auto and a/c, needs the usual, currently on 'Static Display'
85 Westy. 2l aba/1.8 head, diesel doner hardparts, running work- in- progress

[vanagonjr]

[?Waldo?]

[denwood]

As Andrew quoted, you basically remove some material by sanding the pump body as I described, bringing the gears effectively closer to the top plate when it's bolted in place. Machining would be preferable, but wet sanding on a flat surface with even pressure will get you a few thousandths quickly.

It took me three tries (sand, assemble with plastigage, torque cover plate bolts, disassemble, measure) to get to around .003". About 30 minutes.
_________________
Cheers,
Dennis Wood
The Grape

[vanagonjr]

First thanks to everyone for this excellent info. I have not yet taken apart my new diesel pump, but I assume I will need a new gasket when I mesh it with the ABA pump body, but where does one purchase the gasket, I have not been able to find a listing for such; are you forced to re-use the old one ....or use only sealant?

I had not planned a new oil pump (providing it measures OK per Bentley), since I have run several (Honda) cars well past 200K and all those were on original pumps, but is it recommended that one just buy a new pump?

My ABA has approx. 140K on it. I had planned to see what the oil pressure is first.
_________________
John - 86 Wolfsburg Westfalia "Weekender"
Flint reversed 1.8T W/Passat 5-Speed
LiMBO (late model bus club) www.limbobus.org
LiMBO is on Facebook too! https://www.facebook.com/groups/
FAQ thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=525798

[Mike Pratola]

So after a few days of oil pressure / priming bliss, I'm back to square one. Started the van yesterday and it would not prime, showed about 7# on the gauge, the oil pressure light wouldn't go out and the lifters were clacking. Either the pressure relief valve is hanging up again, or the aluminum pump housing is worn and there's too much clearance between it and the pump gears. I'm not buying the ' you gotta run 50 wt ' theory yet, I've seen good oil pressure on 10w-40 as in my earlier post. Either way, I can't trust it in the long run and am going to install a new pump. My question now is has anyone ever tried pressing the pump drive shaft out of the gears and switching them instead of buying two pumps and switching the housings and pick ups? I've got a call into FAS to see what they use, it just seems like a waste to have the leftover parts hanging around, and custom fabricating a pick up tube for a gas engine pump looks cost prohibitive.
_________________
67 Bug, currently in hibernation
78 Westy, auto and a/c, needs the usual, currently on 'Static Display'
85 Westy. 2l aba/1.8 head, diesel doner hardparts, running work- in- progress

[?Waldo?]

There are no gaskets between the parts of the oil pump.

[Mike Pratola]

Just a follow up. I ordered a new Febi oil pump for a diesel engine. With some creative use of fixtures and tools I was able to press the shafts out of the old and new pumps and switch them, so no need to buy the diesel and gas pump and swap parts. As per denwood's suggestion on a previous post, I checked the end clearance and found it in the .004 range, so I disassembled the pump and lapped the housing on a piece of thick glass and 400 grit wet dry until we had .002. Using 15/40 wt, the engine primes instantly, shows 30#s at idle hot and 50#s at cruising speed hot. Out of curiosity I checked the clearance between the gears and the housing on the old pump and it was in the .007 range, the new pump was in the .004 range, so that must be the culprit. On a side note, the Febi pump seems to be a much stouter unit than the OEM, the castings seem thicker and the machine work is nicely finished. Also, my local machine shop/engine builder tells me he never installs a new oil pump in anything until he disassembles it and checks all the clearances, relieve valve operation, and runs it with a drill in a container of oil to make sure it's OK and primed.
_________________
67 Bug, currently in hibernation
78 Westy, auto and a/c, needs the usual, currently on 'Static Display'
85 Westy. 2l aba/1.8 head, diesel doner hardparts, running work- in- progress

[vanagonjr]

OK, we discussed desired cover clearances, I am wondering about desirable backlash. Bentley lists 0.0079" max, I am getting 0.005" on my old ABA pump.
I checked the new diesel pump for comparison: 0.003-0.0035"
While 0.005" is within spec, is it more than what is desirable?



I measured the cover clearance by straight edge and using plastigauge
New diesel pump:
straight edge: 0.004"+ on one gear, 0.002" one the gear with the drive
Plastigauge: .004-.005 one one gear, 0.0025" on the gear with the drive
Old ABA pump:
straight edge: .004"
Plastigaguge:.005"

I'll sand the housing later to lower the clearance.
_________________
John - 86 Wolfsburg Westfalia "Weekender"
Flint reversed 1.8T W/Passat 5-Speed
LiMBO (late model bus club) www.limbobus.org
LiMBO is on Facebook too! https://www.facebook.com/groups/
FAQ thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=525798

[denwood]

John, if Bentley spec .008 (max) then .005 shouldn't be a big concern. A few specs out there suggest .002" is what a new pump should be approx. when new.

If your cover/gear clearance is .002/.004 on the new pump, then reducing that clearance may take you to cover contact on one of the gears. So if you do reduce the cover/gear clearance on the new pump, do it carefully! We know this part will likely wear faster than any other component on the engine, so nearing contact (.0005") is probably ok...it will only increase with age. The pump housing is aluminum, the gears steel, so one would expect greater clearance with a hot pump body. I see mention in the performance world of cast pump bodies/steel covers likely for this very reason...better tolerance when hot.

With .002" variance between the pump gears/vs housing, one wonders how flat/true your housing and top cover are. I'd pop the pump gears out and check them as well to see if there is .002 difference.

I towed my Hobie 18" catamaran back from the lake yesterday (with an added two sea kayaks on top) and the oil pressures and temps with 5w30 synthetic stayed very healthy. At 3500 rpm, hot oil pressure was 4.5 BAR. The Mocal oil cooler really performs well under heavier load..picture this, but with two 14" sea kayaks piled on

_________________
Cheers,
Dennis Wood
The Grape

[vanagonjr]

[MarkWard]

Finally found this thread. I too have the exact same symptoms, but have not pulled the pan yet. Just researching at the moment. It does seem crazy to buy to pumps to end up with one useable one for a temporary project.

Mike, I'd like to know a little more about how you were able to swap the shafts. Did you need to swap both shafts or just the pump drive shaft? I am going to drop the pan and see what the PO had done, but expect based on my reading, a good pump will solve this. mark

edit update. I dropped the pan yesterday on my inline 2.0 and removed the pump. It had .005 to .006 end clearance. I removed the relief valve, but it was not stuck open. Cleaned the bore and the piston and reassembled the relief valve with some royal purple assembly lube. I removed about .003 from the pump housing to get the clearance closer to .002. Put it all back together with fresh oil and started it up. Engine got oil pressure almost immediately when it had zero pressure when I drove it into the garage. Using all the original parts.

The pump seemed to have very little wear and was a hybrid of the diesel and ABA pump. Since this seems to be a reoccurring scenario, I wonder if the problem might be related to mixing parts. Anyhow, the other thing I did was a slight film of gasket eliminator between the two parts. I wanted to ensure that it did seal properly after sanding the case down. If it sucks air, that will affect how it primes as well. I also faced the sump plate and removed a little bit of flashing in the top of the pick-up tube. I'll post back after I have some more time starting and stopping. The van is not for the road at this point, I just need it to be running to move it around. Thank you for the above write ups. mark
_________________
☮️

[Zeitgeist 13]

[Vanagon Nut]

So in an effort to fix a no pressure at cold start issue, I followed what other folks did and shortened the gear housing a little to reduce axial gear play. Before I did the work, play was about .004-005". After work was done, at most spots, the red Plasti Gauge showed. 002" and the most I saw was about .004" Of note, as i reduced the height of the pump housing, the post for the slave gear started to contact the emery cloth. Since there ended up being less than .002" between that part and the pick up tube plate, I found that careful use of a Dremel bit created a ~ .006" gap at those parts. On the new diesel pump, the end of the drive gear shaft and slave gear post have a much larger gap between them and the plate.

In an effort to mimic the part being mounted at the engine, I installed all 4 bolts on the pump. A piece of 2x4 with a hole for the pump drive shaft, and another piece of wood clamped to that as a brace, aided in holding the work while torquing the fasteners.

While doing the work, I also remeasured gear lash of the used ABA pump using spare feeler gauges cut to size. A .006" gauge is a tight fit and an .007" will not fit. But....

Even though that gear lash is within spec, considering the added length of the diesel pick up tube, and volume of oil, would I be wise to replace the ABA pump?

Any tips on swapping a new drive gear onto the used ABA drive shaft would be welcome!

Neil.

edit

some pics of work

new at install diesel Vanagon oil pump pick up tube face. It had literally minutes of use and though it barely caught my fingernail, there is a manufacturing gouge in lower RH of image near relief valve

plate after 400 grit emery paper, water, on thick piece of glass. Plasti Gauge results also shown.

plasti gauge, wood support/brace

plasti gauge results

slave gear post, Plasti Gauge after material removed to clearance

_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Vanagon Nut]

So I'm sure others already know this but some observations playing around with ABA and Diesel pumps.

The ABA drive gears fit the diesel gear housing. In my case, doing so reduced gear lash by ~ .003". The ABA drive shaft fits tighter to the diesel housing so reducing that lateral play reduced the lash. I have no idea how much that lateral play affects gear lash when the pump is installed. I'm pretty sure the recess at drive shaft hole on housing fits the boss (?) at the block.

Also, don't reduce the gear housing any further than .002" Doing so will likely cause the pump to seize ** after fastners are torqued.

In spite of checking clearance with straight edge and Plasti gauge, I decided to try and remove pits on the housing end face. D-oh.

I think I can hand lap the housing to the bottom of the gears. We'll see.


** edit: I installed all 4 bolts while the part was on the bench. Without the engine block to support the housing, it's possible the two larger bolts (with nuts, washers) were stressing the housing and in part, was causing pump to seize. I really doubt it but maybe. Regardless, after turning it by hand many times with just the small bolts installed, it started to turn easily.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[Vanagon Nut]

[Vanagon Nut]

First off, thanks SO much to others who posted here on this topic. Reducing gear axial play seems to have fixed the issue. Refacing the pickup tube didn't hurt either. So far, so good.

With the repaired used ABA pump + new diesel pickup tube installed, pump primed by hand, I let the engine sit overnight. 1st start next day, pressure gauge showed good pressure nearly immediately. I then re installed the blue OE pressure switch. Next day, 1st start, at idle, red light blinked twice before shutting off. It appears oil leaked out of the head while swapping in the OE oil switch. I assume that caused the red light behaviour.

The head was (is) used, it had at least one set of damaged threads (e.g. for coolant flange) so even though the pressure switch threaded in just fine, I'll need to watch for any leaks at pressure switch and head. edit: I'd "constantly" kept checking that union by hand and didn't not feel any leaks. Yesterday, I saw a patch of oil on cardboard on ground beneath the head. I hadn't noticed or seen that prior.

The new pump had a questionable quality at the blind M6 bolt hole. Manufacturer metal shards were still in the hole and the bolt did not turn easily at that hole even after shards were cleaned out. As noted, gear lash appeared to be the same as on the used pump I re installed. There was a yellow paint mark on one of the M6 bolt heads. I can't recall if it was at the bolt at blind hole. I'm sure the pump works but it may be relegated to my 15º ABA as a spare. (though i'd guess something like the con rod bearings or piston skirts would wear out before the pump)

I measured the oil passage hole in the ABA block. Its relatively small so the smaller opening in the Kolbenschmidt pump is likely a non issue.

Neil.
_________________
1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN