1997 GMC Suburban radiator transmission lines

CHEATHAM777

MEMBER
1997 GMC SUBURBAN
V8
4WD
AUTOMATIC
141,000 MILES

Im having trouble with my radiator and the lines. I recently installed a new radiator and connected both upper and lower oil lines to the radiator. Connected both upper and lower tranny fluid lines to the radiator. Vehicle ran for about three miles and the transmission dis-engauged. I loosened the lower tranny fluid line going into the radiator and the tranny en-guages but now im loosing tranny fluid from that lower line. Seems to be some kind of vaccume or pump problem but idk? There is fluid coming from the line when the cars in drive but when its attached snug with the radiator the transmission wont engauge at all. Nada. Theres no flow. Do I need to bleed the tranny lines like you would the brakes? What did I do wrong installing this radiator? Can you help me?

1 Reply

MATHIASO

MECHANIC
1,209 POSTS

Hello cheatham777_

Happy new year

You do not bleed tranny lines like you would for the brake lines and you did not do anything wrong installing the radiator.
Here is what you need to know and what you need to do:

For an automatic transmission to function normally, the fluid level must be between the "full" and "add" marks on the dipstick. If the fluid level is low, the transmission may slip or engage slowly. If the level is too high, the fluid can become mixed with air (aerated) causing shifting problems, slippage.
Check the level when the transmission is hot, with engine idling and the transmission in Park. Moving the gear selector thorough each gear position prior to checking the level will help assure an accurate reading. Vehicle must be parked on a level surface or raised on a lift. Jacking up the front wheels will tilt the vehicle and give an inaccurate indication of the fluid level. Therefore, all FOUR wheels must be raised off the ground and the vehicle must be properly supported by four jack stands .