Transmission isn't shifting properly 2004

[Kkramer04denali]

Had my transmission fluid and filter changed by a questionable mechanic and now my transmission is having a hard time shifting,
On a separate issue I'm facing is no brake pressure I've replaced the master cylinder and bled brakes still no pressure, when foot goes to floor the service brake light is on as well as stability

 

[rockola1971]

Had my transmission fluid and filter changed by a questionable mechanic and now my transmission is having a hard time shifting,
On a separate issue I'm facing is no brake pressure I've replaced the master cylinder and bled brakes still no pressure, when foot goes to floor the service brake light is on as well as stability

Very good possibility the wrong filter was installed (there is a short and a tall neck version which is dependent on type of pan installed) or the filter neck was not installed properly and now the Oring seal is leaking.

As for the brakes. You typically cant bleed brakes the old school method way on ABS equipped vehicles. There is air trapped upstream of your ABS solenoid manifold, especially since the master cylinder was replaced. The only way to get it out is actuate the brakes into a locked up scenario or with a bidirectional scanner like the Tech 2 or equivalent. The Tech 2 actually has a one man automatic bleed feature built in. It uses the ABS pump to "pump up" your brakes instead of the old pump, hold, crack bleeder open and then close bleeder, release brake pedal. Service Brake Light on means air trapped in the system. Stop pushing pedal to the floor, this can damage seals in your new master cylinder.

 

[Kkramer04denali]

Great advice, went ahead and ordered an obd2 scanner with abs function, I checked the filter... As I removed the pan I noticed coolant in the transmission I'm sure it was intentionally done by the mechanic, how much coolant or water would damage the transmission? Any way to fix with out flushing?

 

[rockola1971]

Great advice, went ahead and ordered an obd2 scanner with abs function, I checked the filter... As I removed the pan I noticed coolant in the transmission I'm sure it was intentionally done by the mechanic, how much coolant or water would damage the transmission? Any way to fix with out flushing?

Why on earth your "mechanic" would put coolant in your tranny is beyond me but your tranny and engine use the same cooler which is the radiator. You could have a breach in the radiator that leads to the tranny cooling section. Check your engine coolant to see if it has tranny fluid mixed in. Either way the coolant is going to cause all kinds of problems since it is NOT hydraulic fluid like tranny fluid. Its properties are nothing like tranny fluid. You have a mess on your hands.

 

[RAMurphy]

Concur. Check your radiator. For the life of me, I cannot understand why coolant would be added to the transmission unless there is an issue with your radiator or your mechanic is totally incompetent. Either way, you have a major issue on your hands. Not sure how long the transmission has been operating with the coolant or how much coolant has contaminated the system and whether associated damage occurred. However, you will need to definitely need to "flush" your transmission and lines to remove that contamination.

 

[OR VietVet]

Great advice, went ahead and ordered an obd2 scanner with abs function, I checked the filter... As I removed the pan I noticed coolant in the transmission I'm sure it was intentionally done by the mechanic, how much coolant or water would damage the transmission? Any way to fix with out flushing?

OK, I GOTTA KNOW, how did you notice that coolant was in the transmission? "I'm sure it was intentionally done by the mechanic" does not make sense. What made you use a "questionable" mechanic, to begin with? If you see coolant in the trans, you bring that up as a point that in your mind it should not be there but you are sure the mechanic put it there on purpose! Like has been said, coolant and trans fluid are not supposed to be mixing together. That transmission only has a chance if it is flushed out immediately and even then, the damage may have already been done. Also, change that trans filter again as well. I would also not even hesitate to replace the radiator because it either caused this problem or it also has trans fluid mixing internally. I would also flush the cooling system when install the radiator and replace the thermostat. I was gonna try to look up the correct Genuine GM radiator for you but it seems, in your mind, that all 2004 models are exactly the same, since you did not give any other info with your post. Sometimes this reminds me why I would get frustrated with people that would drop off their rigs for work at my shops. "What year and model and engine do you have"? "Heck, I don't know". Inevitably, these were the same people that would freely fling out statements about how the tech did not know what they were doing.

I am sorry, if this rubs the wrong way, but sometimes I/you just have to justify some statements and I am not a mind reader when it comes to knowing what all your 2004 info is. We here can only go off of the info shared and in this case, there is some accusations and unclear statements made.

By the way, welcome to the forum.

 

[Kkramer04denali]

OK, I GOTTA KNOW, how did you notice that coolant was in the transmission? "I'm sure it was intentionally done by the mechanic" does not make sense. What made you use a "questionable" mechanic, to begin with? If you see coolant in the trans, you bring that up as a point that in your mind it should not be there but you are sure the mechanic put it there on purpose! Like has been said, coolant and trans fluid are not supposed to be mixing together. That transmission only has a chance if it is flushed out immediately and even then, the damage may have already been done. Also, change that trans filter again as well. I would also not even hesitate to replace the radiator because it either caused this problem or it also has trans fluid mixing internally. I would also flush the cooling system when install the radiator and replace the thermostat. I was gonna try to look up the correct Genuine GM radiator for you but it seems, in your mind, that all 2004 models are exactly the same, since you did not give any other info with your post. Sometimes this reminds me why I would get frustrated with people that would drop off their rigs for work at my shops. "What year and model and engine do you have"? "Heck, I don't know". Inevitably, these were the same people that would freely fling out statements about how the tech did not know what they were doing.

I am sorry, if this rubs the wrong way, but sometimes I/you just have to justify some statements and I am not a mind reader when it comes to knowing what all your 2004 info is. We here can only go off of the info shared and in this case, there is some accusations and unclear statements made.

By the way, welcome to the forum

Concur. Check your radiator. For the life of me, I cannot understand why coolant would be added to the transmission unless there is an issue with your radiator or your mechanic is totally incompetent. Either way, you have a major issue on your hands. Not sure how long the transmission has been operating with the coolant or how much coolant has contaminated the system and whether associated damage occurred. However, you will need to definitely need to "flush" your transmission and lines to remove that contamination.

Incompetent would be an understatement... Should've known better to hire someone from Facebook. To update i have decided to take matters into my own hands.
Flushed the transmission 3 times
Replaced shift solenoids and switches
Replaced the upper and lower lines
new auxillary cooler
radiator and related hoses
Water pump.
Every gasket from valve cover to oil pan has been replaced.
I went to put it in gear and it doesn't want to go from drive to first, second or 3rd. Reverse neutral and drive feel loose. Is the shift cable to blame or what could be the cause? Any suggestions/advice would be appreciated

2004 Yukon Denali

 

[B-train]

Wow! Sounds like you are plenty competent to do your own work, too bad for the FB fiasco...... but I do understand paying people some times for things to get done if you just don't have the ability or time.

So, I gather the shifting feels weird? If it goes into each gear as you move the shifter, then it's not the cable. Have someone go through all the positions while you watch the shift arm on the side of the trans. I have seem the bushings get worn or dry rotted and then get sloppy......but that usually only last so long before the cable comes off and you have a shifter that operates like your kids Playscool jeep.

It's also possible you have crap in the valve body from this experience and it's preventing the proper fluid flow

 

[rockola1971]

I would bet that every seal is no longer holding back hydraulic pressure (tranny fluid) due to the antifreeze in the tranny. This tranny is going to need to be dropped and rebuilt.