zero trans fluid pressure

[papabluetexas]

2000 4.0 v6 explorer. 120,000 miles. Last Filter/Fluid change at 75,000 miles. O/D lite came on intermittently. My Son was driving the explorer and it hesitated up a hill then stopped. No previous slippage problems or anything befoe that. Fluid level was fine. Had the vehicle towed to my home. I went into foward for ten feet, reverse for ten feet and then nothing. The truck has not been used for towing and has original factory equipment. Trans Fluid is Mercon V. Changed Filter and Fluid. Fluid was grey not completely black. Filter appeared clogged. Suv shifts into Drive etc, do not hear anything. IN 4x4 High and Low I hear a click. No previous electrical or wiring problems. I raised all four wheels and can move front wheels and back wheels move. I check the trans fluid pressure, it is zero. Removed trans fluid connections to radiator, nothiing, removed aux cooler connections, nothing. Dropped the trans pan again. Fluid is once again grey in color. Pan drop requires about 4 to 5 quarts of fluid for refill. From reading existing posts, I believe is is either a solenoid or shift motor. Any advice would help. My thinking even with a bad shift motor the trans fluid should flow through the system.

 

[gijoecam]

120,000 miles. Last Filter/Fluid change at 75,000 miles.

Ultimately, I think that may be the root cause. Regular fluid and filter changes every 30k are pretty important on these transmissions. Water under the bridge at the moment... You've got bigger fish to fry.

O/D lite came on intermittently.

And what code was stored when that happened?

Fluid was grey not completely black. Filter appeared clogged. Suv shifts into Drive etc, do not hear anything. IN 4x4 High and Low I hear a click. No previous electrical or wiring problems. I raised all four wheels and can move front wheels and back wheels move. I check the trans fluid pressure, it is zero. Removed trans fluid connections to radiator, nothiing, removed aux cooler connections, nothing. Dropped the trans pan again. Fluid is once again grey in color. Pan drop requires about 4 to 5 quarts of fluid for refill. From reading existing posts, I believe is is either a solenoid or shift motor. Any advice would help. My thinking even with a bad shift motor the trans fluid should flow through the system.

Yes, the trans fluid should be pumping any time the engine is running, even if it's not going anywhere. I suspect something let loose between the trans and motor, or the pump took a dive. Either way, it means dropping the trans to assess the damage.

I would not suspect it has anything to do with the t-case given the symptoms you described.

 

[BrooklynBay]

Did you check the pressure with a 0-300 PSI gauge? Disconnecting the cooler line to check the flow only works on an older A4LD transmission. Your 5R55E has a part in the valve body that cuts the flow to the cooler when it's cold, then opens up to allow cooler flow when it gets warm/hot. There is a way to remove this part in the valve body, and bypass it, but I don't think that this is your problem. You could have a clogged valve body, blown valve body gaskets, loose valve body bolts or a bad EPC solenoid. The DTRS could be bad or out of alignment too.

 

[papabluetexas]

Did not check with a pressure gauge but with everything together and full of fluid, i let the vehicle idle for about 20 minutes. I have a code reader that reads type II codes do not know if it will pick up trans codes. All codes are normal on my $60.00 reader.Can get a rebuilt trans for $1100. I want to do more investigating once it gets warmer here in NJ hopefully on Saturday. Thanks for your help.

 

[papabluetexas]

more investigation

Today I checked all the vb solenoids Epc checked fine around 5ohms. Others checkout at 26 ohms. However the solenoid on the same line (side) as the epc but the at the other end only reads 10.5 ohms and does not have a strong click to it when 12volts is applied. All others have a strong click. EPC screens look clean and all fit into place without movement and appear to have no wear. I think the "bad one" controls the converter clutch PWM. Does anyone think this could be my problem. Explorer does not move in any gear. I originally described my problem as "Zero Pressure Flow". I plan to purchase a pressure gauge to confirm that is the case.Before I do a complete rebuild I plan to purchase and install six new solenoids. I have also investigated buying a new pump as this has not been ruled out yet.

 

[BrooklynBay]

The EPC & TCC solenoids are modulated, and the only true way to test them is with a scanner sending a modulated signal to them. You could check WWW.800700Tran.Com for the parts that you need.

 

[papabluetexas]

I have got a lot of information from this forum and appreciate everyone's help.
Thanks! Shouldn't the resistance of the TCC solenoid be around 28 ohms. Also forgot to mention I did a visual check of the vb gasket. Appears fine. Fluid in the pan on the second drop was grey but further finger inspection no smell and rubbing between my fingers appeared red. Is the trans fluid pump a part of or driven by the torque converter. Still learning. Have read many fine post. I guess the zero pressure with my little knowledge is still a mystery to me. I believe after running in idle for 20min and going through a couple of gear changes something should have come out of the cooler input lines. However,it was around 30 degrees that day. I will order the 6 solenoids today!! Should the TCC solenoid have a red screen on it mine does not only two holes.

 

[BrooklynBay]

Don't order solenoids until you do a pressure test. The parts might be good. The pump is connected to the back of the bell housing where the torque converter goes into.

 

[papabluetexas]

thinking

i thought about that but for both the epc and tcc ;the cost is less than a mercron v refill, new filter and gasket. My labor is cheap but still time spent. The four other solenoids are cheap.I know I still have to complete the refill but I would like to torque the bolts on the solenoids and pan and see the torque converter work. From everything i read 10.5 ohms is too far out of specs for the TCC Solenoid , Thanks. I'll wait for your advice. I just read on the forum that someone added a resistor to the TCC and made it work! I don't think my trans has very serious problems, if so I will accept it. It's Never been abused for the last 80K miles. I was a little lax in the last fluid change. The pan is clean no metal at all. Fluid is grey that's all. Now the TCC solenoid is modulated. If it was always on are you in idle. When it is always off does it matter as to basic movement of the vehicle? I believe an open circuit would make it always off. My real question does it have any control over the trans pump?

 

[papabluetexas]

update zero trans fluid pressure

I changed the epc solenoid and tcc solenoid. Inspected and static tested all others. Also, installed a drain plug in my pan. 10.7 ohm reading was correct for the tcc solenoid same on new one. The old epc solenoid appeared to have a small hole in the end screen. Thought my problem would be fixed. I ordered a pressure gauge don't have it yet. Still appears to be no pressure in the system. Let idle for 20min nothing to either coolers. Would suspect the trans pump. Fluid is perfectly red now, even after idling and shifting through gears for 20-30 minutes. If I have have to go back in I can reused the fluid. Thanks,

 

[papabluetexas]

map sensor

I inspected the map sensor. Is there a way to test this sensor? I took the connector off and did get an error code of P0113 on my scanner.

 

[papabluetexas]

pressure update

hooked up pressure tester to main line driver's side. zero pressure. will test epc side.

 

[BrooklynBay]

It might have a defective front pump, blown valve body gaskets or a defective EPC solenoid.

 

[papabluetexas]

Front Trans Fluid Pump

today, I am going to drop the value body. Is the front pump inside VB? I replaced the EPC solenoid with a new one. Thanks,

 

[BrooklynBay]

The front pump is behind the bell housing, and the only way to get to it is to remove the bell housing (removing the transmission from the vehicle).