VL Oil Pump Oil Inlet Nipple Replacement

[wideglide38]

Hello all, I have a VL oil pump (587-34) with an abuse oil inlet nipple. I have heard there is a replacement kit or procedure to replace the damaged nipple. Does anyone have a line on the repair kit or have/know of a way to replace the nipple?
Thanks, William

[shelbyinparadise]

There is a repro nipple with a hex drive for inserting new nipple into threaded hole, I have used many on 37 and up flathead pumps. Not sure if your oil pump has enough material. FD801079.JPG

[wideglide38]

Thanks Shelby. I had taken a hex nipple with 1/4 NPT off an old pan oil pump and checked thread OD (0.406" at threads just below the hex) and measured the dia. below where threads stop on the VL pump (measured 0.578" dia) body. Certainly not enough material left (walls would be 0.086" thick) if a 1/4 NPT pipe tape is cut into the pump.

[Steve Slocombe]

I agree this replacement nipple does not leave enough wall thickness for the VL oil pump, so have new ones made for each of these repairs.

[wideglide38]

Steve, Do you carry/sell replacement nipples or know where they can be ordered? I also wondered about grinding down the threads and Tig the nipple back up then cut new threads. Question is – Is there a die (specific to Harley’s thread pitch choice) available today to re-cut the threads? Has anyone attempted this approach with success?

[koanes]

The replacement nipple made by Colony and others is not 1/8" pipe, it is a straight thread and should work fine. Operation best performed on a milling machine

[wideglide38]

The replacement nipple made by Colony and others is not 1/8" pipe, it is a straight thread and should work fine. Operation best performed on a milling machine

Kyle, Agreed this should be performed on a mill. I checked Colony (oil pump fitting kit p/n 2374-1) and their fitting has a 7/16-20 thread (nom. OD 0.4375") compared to a 1/8" pipe (nom. OD of 0.405"). Appears I will have less wall thickness with the Colony kit. The OD of the stem below where the threads stop on this -34 VL oil pump is 0.575". The wall thickness with the 1/8 npt would be approx. 0.085" vs. 0.06875" with the 7/16-20 thread on the Colony kit. In either case, I don't think there is enough material to support a shaking engine with a fixed hard line.

[frichie68]

Same problem, also watching for a solution. I took off the top 3/16" of the nipple in an effort to get down to the "good" threads, not confident and no access to a machine shop.
Rich

[Steve Slocombe]

The threads on the nipple are 15/32" x 32 tpi which will not be a common die. As the nipples break in different spots my machinist usually makes a different aluminium nipple for each repair, so I don't stock this as a spare part. It was a poor choice of materials for Harley to go for the pot metal body as the earlier cast steel oil pumps have fewer problems.

[koanes]

The pipe thread is like a wedge trying to crack the hole as it is tightened. You can't comfortably reduce the OD of the fitting as you also have to consider the ID for proper flow and wall thickness. If the job is done properly, with a no stress attachment of the oil line, I cant imagine breaking the pump from use.

[koanes]

I had a look at my Vl oil pumps yesterday. I had forgotten that the pump on my 36 has had the pipe thread pipe nipple installed. Probably done 30 yrs ago, how many miles I don't know. I looked at the 34 pump and was shocked to see how small the opening in the nipple was. Around .140. It's hard to believe cold oil would have much luck passing through such a small opening. Mr. Slocombes thoughts on making a replacement nipple with a smaller thread would work fine if you maintained the small ID. I also took a look at the 33 pump and it has a much larger opening, around a quarter of an inch, so it is odd that they used a tiny feed hole for the late models.

[wideglide38]

I too measured the oil inlet ID and was the approximately the same (.142) and thought about feeding cold oil through such a small opening. I wondered if the pump creates a small vacuum (an opposite affect to creating pressure on the outlet feed). Cold weather days would warrant warming the scoot for 4-5 minutes. Maybe the close proximity of the front head helps heat to the oil reservoir. Being new to VLs it just made me wonder.

[wideglide38]

The threads on the nipple are 15/32" x 32 tpi which will not be a common die. As the nipples break in different spots my machinist usually makes a different aluminium nipple for each repair, so I don't stock this as a spare part. It was a poor choice of materials for Harley to go for the pot metal body as the earlier cast steel oil pumps have fewer problems.

Steve, I measured the outside threads on my -34 pump body and read approximately 0.555" (close to 9/16" or 0.5625" & even closer to 14mm or 0.5512"). With 15/32" equaling 0.4688", there's a difference of 0.0862". I am also reading with my thread pitch gauge, 24 tpi (same tpi for the pan/shovel oil nipples). Am I missing something here? Are the nipple threads straight (they appear straight), tapered or pipe? btw: I did locate a company Taps and Dies (http://www.tapsndies.com/tapsndies.html ) that has hundreds of dies. Thanks

[Steve Slocombe]

The 15/32" x 32 tpi comes from the Harley 0140 special nut which screws on to the oil pump nipple.

[wideglide38]

Thanks Steve!

Can anyone tell me how to get the round valve (noted with arrow) out of the pump body? Is it pressed, screwed or pinned in? I ask, since I plan to have the oil inlet nipple machined off, tapped for a replacement nipple and want to make sure all metal filings are cleaned out before reassembly. Thanks