I did and engine swap along with a new radiator and trans cooler. The trans has been in this truck for 30-years with no trouble. Now, it drives and shifts fine with firm quick shifts but there is no coolant flow through the cooler lines. If I disconnect both lines, and rev it, I get a tiny bit of fluid flowing out of the trans from the upper, or return line. I assume this is due to splash. I have verified there are no plugged lines in or out of the trans. With the engine off, if I blow into the trans outlet line it holds pressure. If I put a vacuum pump on the outlet it will let me pull about 3" vacuum but no more than that. All I can think of is the pump can pump adequate volume to maintain proper line pressure and feed the cooler, or else I have a stuck valve and have lots of line pressure and no relief fluid that would normally be feeding the cooler. I haven't dug-up a flow-diagram yet, but thought someone might have had the same problem and already know the answer before I wrack my brain too hard.
That's an odd one. Cooler flow is not fed by pump pressure, but rather the torque converter rotation. edit: I stand corrected, I just popped open the chassis manual. Looking forward to what you find. Devon
I think its the pressure regulator, best I can figure. Still not sure if it's stuck or just maintaining pressure and the pump is in too bad of shape and hasn't enough volume left for the cooler. I can't find a good enough description of operation to understand how the cooler feed is controlled.
From what I've read in my '67 manual, you just described it in a nutshell. It appears the cooler circuit is only fed by pump flow that's been relieved by the pump's pressure relief valve. So it seems to me, if the relief valve isn't opening, no cooler flow. Devon
At least you agree with my logic, now the question is the valve just stuck, or is there no residual volume to bypass through the cooler. Looks like I get to pull the pan and drop the pressure regulator out if the valve isn't too stuck. Ugh, this trans went back in when the 200-4r I had turned out to be junk. I'm tired of trans fluid and R&Ring transmissions! Sometimes this hotrod stuff just aint as fun as it is supposed to be...
Hate to say it, but that's what I'd do unless someone with more smarts chimes in. I don't envy you; dealing with the relief valve from underneath had me cursing in the '80's when I was in better shape than I am now! Devon
Well, I'll hope for a miracle, I have at least the week to tinker on some other issues and hope the valve might unstick if that is what it is. Thanks for the Ponderance Devon, I always pay attention to your posts for rational thinking when the stumpers come up.
Glad to help, Adam, for what it's worth. I appreciate the compliment! Like everyone else, I'm smart about some things and stupid about others, and all too often I shoot my mouth off and the stupidity comes shining through. Devon
Don't be so hard on yourself Devon. You post way more smart things than not.I always read what you have to say on a given topic. You're a valuable asset to this forum.
It seems the VP pumps have a cooler bypass valve in case of cooler plugging. I think that mine is stuck, and the trans has to come out to investigate . PR valve was fine. I think I'm going to drive it and monitor the pan temp. Have dumped in a can of Lube-Gard; more than one trans-man has told me that it has un-stuck a valve for them.
