top pump bypass valve leaking
05-12-2013, 01:18 PM
#1
top pump bypass valve leaking Was going thru the car for spring cleaning and I found the bypass valve in the "bypass" position. I moved the valve to the "operate" position and it started to leak at the base of the valve handle, actually more like seeping. I operated the valve a few times and cleaned up the leaking fluid ( looks like Dexron III). Leak looks like it has stopped. I placed some shop towels around the valve just in case. Top operates fine and fluid doesnt spray out. I recently purchased this car so I have no idea as to why the valve was in the bypass position. Anyway, as I read thru a few threads, I see reference to using mineral oil instead of Dexron III. Is mineral oil thicker and less prone to leaking and does the system need to be flushed to change to mineral oil? I did some research and the valve is part of the motor/pump assembly and does not appear to be available separately, so if the leak persists, I guess I need to change out the entire pump assembly. Any thoughts?
05-14-2013, 10:44 AM
#2
My guess is the previous owner wanted to operate the top manually, which is what the valve allows when opened.
As far as the leak goes, yeah this happens, in various places too. You might be able to disassemble the pump assembly and replace just the valve, I believe the nylon hoses are just simple compression fittings.
Dexron III was the original GM recommended fluid to use in these pumps. Later a TSB was issued that recommened a change to mineral oil. Not sure why (less likely to stain when it leaks maybe??). The recommendation did not mention the need to flush the Dex III out first, which I had not done either w/ no issues mixing the two. I've also heard of people using hydraulic jack oil, although I would stick to GM's recommendations. You can find mineral oil in the pharmacy near the laxatives.
Good luck.
As far as the leak goes, yeah this happens, in various places too. You might be able to disassemble the pump assembly and replace just the valve, I believe the nylon hoses are just simple compression fittings.
Dexron III was the original GM recommended fluid to use in these pumps. Later a TSB was issued that recommened a change to mineral oil. Not sure why (less likely to stain when it leaks maybe??). The recommendation did not mention the need to flush the Dex III out first, which I had not done either w/ no issues mixing the two. I've also heard of people using hydraulic jack oil, although I would stick to GM's recommendations. You can find mineral oil in the pharmacy near the laxatives.
Good luck.
05-14-2013, 04:31 PM
#3
My guess is the previous owner wanted to operate the top manually, which is what the valve allows when opened.
As far as the leak goes, yeah this happens, in various places too. You might be able to disassemble the pump assembly and replace just the valve, I believe the nylon hoses are just simple compression fittings.
Dexron III was the original GM recommended fluid to use in these pumps. Later a TSB was issued that recommened a change to mineral oil. Not sure why (less likely to stain when it leaks maybe??). The recommendation did not mention the need to flush the Dex III out first, which I had not done either w/ no issues mixing the two. I've also heard of people using hydraulic jack oil, although I would stick to GM's recommendations. You can find mineral oil in the pharmacy near the laxatives.
s
Good luck.
As far as the leak goes, yeah this happens, in various places too. You might be able to disassemble the pump assembly and replace just the valve, I believe the nylon hoses are just simple compression fittings.
Dexron III was the original GM recommended fluid to use in these pumps. Later a TSB was issued that recommened a change to mineral oil. Not sure why (less likely to stain when it leaks maybe??). The recommendation did not mention the need to flush the Dex III out first, which I had not done either w/ no issues mixing the two. I've also heard of people using hydraulic jack oil, although I would stick to GM's recommendations. You can find mineral oil in the pharmacy near the laxatives.
s
Good luck.
11-12-2016, 06:04 AM
#4
I'm resurrecting this from the dead because I have the same issue as the OP.
After having issues with the switch I used the pressure release valve for the first time (to lower the top), after which the valve started leaking/ seeping in the exact location described.
Any body know if these valves can be taken apart & rebuilt OR a part # for replacement ?
After having issues with the switch I used the pressure release valve for the first time (to lower the top), after which the valve started leaking/ seeping in the exact location described.
Any body know if these valves can be taken apart & rebuilt OR a part # for replacement ?
11-17-2016, 02:48 PM
#5
My guess is that there is "packing" around the ****'s shaft that prevents leakage up the shaft (similar to old-school faucets), and that packing is either dried out or has compressed to the point it no longer seals. IIRC, the ****'s shaft goes through the center of a "nut". If so, you might try tightening the nut which should compress the packing and might seal up the leak, or you could remove the nut and see if there is any packing that could be replaced under it. You should be able to find new packing in the plumbing section of a hardware store.
As a last resort, you might be able to find a new valve with similar compression fittings in the plumbing isle at the hardware store. This should be similar in size to what is used on the water line going to a refrigerator w/ an icemaker.
Post up if you find a solution.
As a last resort, you might be able to find a new valve with similar compression fittings in the plumbing isle at the hardware store. This should be similar in size to what is used on the water line going to a refrigerator w/ an icemaker.
Post up if you find a solution.
