Remco Pump Overheats Trans Fluid?

[RVThere]

I have a Remco pump for my 2008 Town and Country Minivan so we can flat tow. Sorry for the long post but it’s complicated…

When the weather is cool, the pump works fine. However, if I’m driving all day and as soon as it gets above 85 degrees or so, I start to get a ‘chirping’ from the pump monitor in the cab. If I slow down, the chirping goes away but only for a while. Here’s what I have noticed and Remco has suggested:

• First happened last July when going through Nebraska. Brought the MH to a Remco dealer in Salinas, KS and they replaced the monitor based on Remco’s suggestion. Two hours down the road, the new monitor started to chirp again.
• For over 1000 miles on the way home, I let the van idle while I towed it with the MH. When idling, I can pull the van in ANY temperature for ANY amount of time with NO chirping.
• Brought it back to my local dealer who installed it. Remco told them to move the ground right to the battery.
• Did not tow the van in heat until a trip to Florida this spring. Sure enough, right past Daytona it started to chirp. Slowed down by about 5mph and the chirp would stop for a period of time.
• Felt the van radiator and upper right (when facing van) was very hot and rest of radiator was cool to the touch.
• On the way home, had to idle the engine while towing to avoid the chirp.
• At one point, I shut the van off and attempted to tow with only the Remco. I got an immediate loud beep on the monitor and had to pull off to idle the van again.
• Called Remco and spoke with the head of Tech Support.
  • He wanted to know if the Remco monitor blue wire was attached to the battery or the alternator.

i. I checked and it was hooked to the battery which was correct

• • He thinks that there is something in the motorhome (2007 Winnebago Tour with a Freightliner chassis) that is turning on when it gets warm outside that lowers the voltage going to the pump.

i. Problem is, you have to drive for a few hours to get the chirp and then try to get a meter on the connection to see if the voltage dropped???
ii. If the power is hard wired to the battery, what would cause the drop in voltage? And why would that voltage increase if I slowed down?

My theory is that the transmission fluid is overheating which causes the pump to lose suction (can transmission fluid boil?) which makes the pressure switch send a chirp signal to the monitor. Remco did not think that was the cause.

Anyone hear of this problem or have any ideas?

[EngineerMike]

Tom- you can take the temp of the tranny pan w/an infrared thermometer (or any other parts in question like the radiator @ several places) to verify.
Yes, tranny fluid can get hot, even boil (@ which point you usually get expanding fluid/gas burping out the fill point/dipstick). If you boiled yours (probably not, ~600° & very dangerous as it can ignite easily above ~450°) or even got it overly hot, I would expect to see a change in color to more of a brown.

IIWY, I'd take temps @ various places cold, then @ 10 miles, then 20, then every 20 miles or so to establish a curve on how things are heating up, and include ambient temp for a proper check. You can use this info to "assist" Remco assisting you.

If this turned out to be something esoteric to your toad, you could try a relay to switch on the electric radiator fan on the toad (I'm assuming yours has one) while towing. No guarantee that cures your chirping but should help temps if you are getting some fluid circulation to the radiator; we probably don't get much ram air across toad grills.

[RustyJC]

Since one area of the radiator (probably where the tranny cooler is located) is hot and the remainder isn't, I'd suspect lack of coolant circulation as more of a problem than operation (or lack thereof) of the radiator cooling fan. Supporting this theory is that, when you idle the engine, you don't have the problem - when you idle the engine, the water pump is circulating coolant over the radiator tank tranny cooler.

If transmission fluid temperatures are indeed the problem, adding an oil-to-air cooler in the transmission fluid line to the radiator could solve the problem if you can find a location to get it into the airflow while it's behind the MH. This way, you're not relying on engine coolant to carry the heat away.

Rusty

[EngineerMike]

Rusty's suggestion is better than mine, and probably easier to implement as well. Still need to figure out what's up w/the Remco chirp to make sure you are addressing the real problem.

[Gary RVRoamer]

I'm not sure Rusty's point about the water pump cooling is conclusive. When the engine is idling, the fluid in the transmission is circulating on its own with no need for help from the Remco pump, so it could be THAT that is stopping the chirp rather than the radiator cooling.

I amazed that Remco doesn't seem to know what conditions can cause a "chirp". Maybe its because the company has new owners and perhaps a new engineering staff as well?

In the meantime, an auxiliary tranny oil cooler or perhaps an aux electric fan for the radiator is worth a try. If it stops the problem, you know the chirp is related to fluid temperature somehow.

[RVThere]

Thanks for the feedback. I just went on line and bought a IR temp gun from Amazon to get some accurate readings (plus it was neat tool that I didn't have).

I tried to tap the power going to the Remco pump and connect the electric fan on the van too. This was a 'remote' fix done at the Flagler Beach campground on Palm Sunday. That only accomplished blowing the fuse in the Remco monitor so I ditched that idea because I didn't want to put a bigger fuse in and fry the wiring. That would have been a REAL problem.

Also looked into a separate trans fluid cooler with a fan and a 170 degree thermostat (used on monster trucks). It was $200+ which is no big deal but there does not seem to be a good spot to mount it where I'd get some cooler air. The rear diesel does not help the heat situation either.

As a final complication, 2008 Town and Country's don't have a transmission dip stick. The dealer has a dip stick and has to hook the van up to the computer to read the temp of the trans fluid. Then they go to a chart to see how high the fluid should be on the dip stick.

A complex problem but still interesting!