Yukon braking when i press the accelerator in first gear.

[Mohammed Saqer]

I have i 2004 gmc Yukon xl with the 5.3
I just got it from a family friend for like 600$. It was sitting for almost 8 months
Changed the oil and coolant
Thankfully it had an empty gas tank at the time
Drove it home and everything seemed fine at first
But the next day i got out to get some suspension parts and it started acting up
Whenever i let go of the throttle in low speeds like 15-25 mph. It kinda feels like it's braking whenever i try to accelerate or touch the throttle. And the rpm drops down and then i hear a clunk coming from the drive shaft is if it was just engaged when i stay on the gas pedal and then it would accelerate
The clunk is exactly like when you put it in reverse or when you're just cruising with your foot is off the accelerator and then suddenly put your foot on the gas pedal
The engagement of the transmission
((( Sorry if my English is barely understandable . I'm still learning )))
Any info on what this could be would be greatly appreciated. Thanks

 

[justirv]

I have i 2004 gmc Yukon xl with the 5.3
I just got it from a family friend for like 600$. It was sitting for almost 8 months
Changed the oil and coolant
Thankfully it had an empty gas tank at the time
Drove it home and everything seemed fine at first
But the next day i got out to get some suspension parts and it started acting up
Whenever i let go of the throttle in low speeds like 15-25 mph. It kinda feels like it's braking whenever i try to accelerate or touch the throttle. And the rpm drops down and then i hear a clunk coming from the drive shaft is if it was just engaged when i stay on the gas pedal and then it would accelerate
The clunk is exactly like when you put it in reverse or when you're just cruising with your foot is off the accelerator and then suddenly put your foot on the gas pedal
The engagement of the transmission
((( Sorry if my English is barely understandable . I'm still learning )))
Any info on what this could be would be greatly appreciated. Thanks

@NickTransmissions is the resident expert here. There are plenty of knowledgeable people here to help. You may not get too many responses today, as it is a long holiday weekend.

 

[strutaeng]

Are there any dash lights on? If the Service Engine Soon light is illuminated, get that checked to see what code is on.

ABS/Brake lights on? If so, remove the ABS fuse under the engine fuse block and see if that does anything. I'm suggesting this since you mentioned you think you have some "braking" when driving. The brake control module could be wrongly applying power to the brakes?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[PPV_2018]

At first i was thinking like engine braking, maybe an issue with your brake calipers.

But with a clunk sound, it sounds like a transmission issue, maybe torque converter ? Far from an expert on transmissions, so I’m just speculating.

 

[Fless]

What does the transmission fluid look like (brown, pink, red) and how does it smell? When up to operating temp, how is the fluid level on the dipstick?

 

[Mohammed Saqer]

@NickTransmissions is the resident expert here. There are plenty of knowledgeable people here to help. You may not get too many responses today, as it is a long holiday weekend.

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

I'll differently be more active now that i know there are Tahoe and Yukon forums like this.
Thank you for welcoming me and special thanks to everyone replied to my post.
Sorry for not replying in time. My browser doesn't show me notifications even after enabling them for this URL

 

[Mohammed Saqer]

Are there any dash lights on? If the Service Engine Soon light is illuminated, get that checked to see what code is on.

ABS/Brake lights on? If so, remove the ABS fuse under the engine fuse block and see if that does anything. I'm suggesting this since you mentioned you think you have some "braking" when driving. The brake control module could be wrongly applying power to the brakes?

Thank you for replying to my post.
Sorry for the late reply.
Yes. The abs comes on once in a while
And i also have a problem with the brakes. The fluid doesn't sometimes reach the calipers at the first time i press the brake pedal
Changed the oil and i did bleed the brakes and it's still like this
I don't know if it has anything to do with braking only when pressing the gas pedal though

 

[Fless]

After sitting for a long time, I would suspect a stuck caliper in addition to an ABS issue. When you bled the brakes, were the calipers able to "float" on the slide pins? The caliper pistons may also be sticking.

 

[justirv]

Thank you for replying to my post.
Sorry for the late reply.
Yes. The abs comes on once in a while
And i also have a problem with the brakes. The fluid doesn't sometimes reach the calipers at the first time i press the brake pedal
Changed the oil and i did bleed the brakes and it's still like this
I don't know if it has anything to do with braking only when pressing the gas pedal though

I had problems getting a good brake bleed on mine. Solved that issue with a Tech 2 clone. ABS/Master Brake bleed made a huge difference in pedal feel and initial bite. As @strutaeng and @Fless suggest, you have other bigger issues to address first.

 

[noodlesandsam2]

check all fluid levels - transmission could be low. Check underneath for overall condition of frame, gas lines, brake lines - check for rust. If you are in a salt belt area, that needs to be understood. Also, as these get to higher mileage, the front hubs wear out, and you get low speed ( crawling speed ) kickback from ABS.