GT750 Oil Pump Leak Conundrum

[JomamaGT]

Well, got the right gasket from Reinert but the pump is not leaking between the upper and lower housing halves. It appears to be coming from around the actuator arm where it enters the upper housing. I don't think any seal is involved and the surfaces appear to be machined to very tight tolerances. Has anyone seen this anomaly? I am about at my wits end. I would buy a new pump if that were an option. Does anyone rebuild these things? I have a 1974 pump - can I use the upper housing on my 1976 pump? Or should I try to use the 74 pump as is?

I know this comes off as desperate but I really need some help. Thanks guys.

[GT750Battleship]

Hi,never seen the pump do this on any Suzuki that I've owned.I now have a GT750A,if you have a look on the Web the pump is pretty well described,search. Pink Possum GT750 Oil Pump,this explains the working of the 2 different Pumps that were fitted to the Suzuki GT750! Hope this helps out?
PS,just seen your post on "Kettle Clinic" as well,good luck with fixing the problem,please let us know how you get on....
Cheers,
GT750Battleship.

[tz375]

The 74 is identical in fit and function and should drop straight on. Don't strip it - just fit it. The tops will be different, so just fit the complete pump.

I haven't seen that mode of leaking before either. Can you detect any wear in the shaft or freeplay? Remove the nut, spring and lever and see if there's any play in it. If not, that's probably not the leak source. I can take a look at it if you want.

The shaft is retained by a tiny pin from the lower face and it goes through a groove in the shaft to locate it laterally. A little heat is enough to get that out. The shaft does have an O ring to seal it and it is entirely possible that the seal was damaged by cleaning solvents. At this stage I have no idea if the original was a round doughnut shaped seal or if it was a square seal. I'll dig one out later and see what I can find out.

[JomamaGT]

Really good stuff. Had confirmation from our English friends of such a leak and existence of a seal. Look forward to hearing from you about that seal!

[tz375]

It's odd looking seal. I have not had time to check seal catalogs yet, but here's a link to what's in there.

http://pinkpossum.com/GT750/Oilpump.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;


If anyone has a lead on that seal I'd like to get some. It's an odd little thing.

[JomamaGT]

Can you guys take a look at this part described on oil pump boot and tell me where it goes?

oil pump boot.jpg

Can't find it on the parts diagram.

[tz375]

That's easy. It fits in the opening in the oil pump cover where the cable or linkage rod comes in.

[JomamaGT]

Yes, just heard that over at the Kettle Klinic. Please run your disregard checklist!

[tz375]

Just for sh*ts and giggles, you could pressurize the oil tank slightly (don't go mad there) and see if it forces more oil out of the shaft.

If it does, it will confirm the diagnosis.

Reiner has informed me that neither Suzuki nor the aftermarket supplies that odd sized seal, so I'm on the trail of alternative solutions

[JomamaGT]

tz375,

Thanks for providing the solution to my problem. My mechanic installed a seal and the pump is holding. Please let me know if you are able to source the specific seal.

Jomama

[tz375]

No worries mate. I have some seals on order for delivery next week. If they don't work there are others I can try.

What seal did your mechanic use?

[JomamaGT]

He got it from one of those universal kits - I think he said it was a P5.

[RING_DING]

I have the same problem....oil leaking out from the actuator arm. I pulled the top off the pump last night. Before I undo the nut and spring, is there anything I should be aware of as regards positioning, etc? Also, how do you get that tiny pin out....there's nothing to grab onto!