problem: transmission’s stock oil pump does not flow enough fluid volume to the cooler to keep up with the heat generated, resulting in overheated oil and excessive cool down times
possible solution: add second oil cooler and electric pump that will draw fluid out of the oil pan and pump it to a second oil cooler and let it gravity feed back into oil pan.
question. Looking for a reliable electric oil pump that is designed to flow 250+deg oil constant duty. Also not sure what volume pump I should be looking for.
I don’t think i’m understanding you? your not sure if my cooler is internal or external? obviously it is external. putting a heat exchanger inside a hot transmission wouldn’t do anything productive.
The cooler i am using is cooling all of the fluid that passes through it sufficiently. the problem is that the fluid volume is too low.
the lines on this cooler are 1/2". While the fittings on the transmission are 3/8 quick disconnect fittings. I removed the quick disconnect fittings it had from the factory and installed your typical barbed 3/8" fitting. The theory behind this was to reduce fluid restriction at the fittings. I drilled out the barbed fittings a bit to enlarge the inside diameter to further improve fluid flow.
The hot fluid leaves the transmission and goes to a coupler to enlarge the hose size to 1/2" then to the bottom of the cooler. when the car is running you can’t touch the bottom of the cooler while the top is only slightly warm to the toutch. That leads me to believe that the cooler is removing the heat from the fluid very efficiently. I also don’t think that the cooler is being used to its potential due to the low fluid flow, but the fact of the matter is the transmissions valvebody does not flow the fluid required amount of fluid to cool the transmission. That is why I want to add a electric oil pump that will pull fluid from the pan, and pump it to a cooler then return it to the pan. I am looking for a pump that will move the pressure and volume that I need to cool this POS.
Your trans fluid is now being pumped using the front pump inside the trans … now what you want to do is add an external high volume pump to draw fluid from the pan and pump it back through ???
whats going to end up happening is you will starve the trans of fluid cause your pump will suck that pan dry …
Truth, well mostly. The pump is a positive displacement pump, which is pressure regulated by a bypass. More pressure = more flow. Just like an engine oil pump, the more RPM the more flow and pressure (until you overcome the regulator, at which point the pressure remains constant).
How do you know your flow is too low? What is your transmission temperature? How about pressure/temperature in/out of the cooler?
If you are worried just to be worried I would suggest piping another cooler in parallel with the one you already have.
Back when I used to use automatics I would pipe the transmission line through the radiator then through the aftermarket cooler. I never had problems.
If you are going to get an aftermarket pump I strongly suggest making the loop completely separate from the factory piping, i.e. new inlet and return connection to the pan. Going inline with the existing positive displacement pump will not help you.
as long as you pull the fluid from a point away from the regular pickup and return it to a place that is always submerged in fluid, (ie pickup on one rear corner of the pan and return to the opposite rear corner) and check the fluid with the pump running at full blast, you should be fine.
A larger trans pan is not a option. The electric pump will be constant duty and I will just have to adjust the fluid level with the pump running. I started this thread because i’m looking for a reliable electric pump that will move decent volume at a fair price. The lines for the secondary pump are going to be plumed completely independent of the transmissions existing cooling system. I actually sat down and traced the valvebody to figure out which maze leads where and I had a extremely good understanding on how the pluming was run internally on this transmission. In short fluid leaves the TC (torque converter) and heads for the cooler. From the cooler it goes through a huge maze to lubercate 2 bushings and spray through multiple jets onto the 3 primary clutch packs for cooling. At one point I was thinking about using a external pump to increase the volume and pressure so the clutches would remain cooler + it would have other benefits with no negatives but it would require cutting up my valvebody to do it the way I want to so just getting the temps down will be a good start before I do anything drastic. + i’m starting to get into some off topic info so lets focus on finding a quality electric pump.
power steering pump and an electric motor. dodge neon and 2gnt eclipse have a pretty compact pump with an external reservoir so it would be an easy plumb. some cars even have electric power steering though i dunno how hard it is to separate the pump from the rack.
12v elec motor… the load should be relatively low so you dont need something with ridiculous power. maybe a headlight motor would do the job. dunno about that though.
stuff like that you can scrounge around and put together for next to nothing. and its all automotive grade stuff so it will last no problem.