242 dragging Yukon XL down ramp

[BigAbe75]

We’ve got a new to us ‘15 Yukon XL Denali (6.2), this season. Every time we launch the boat, the front brakes lock the wheels on the ramp and the boat practically drags the car to the water.

Our shorter Tahoe, and my F250 have never experienced this. Same ramp

The first few times I just assumed it was a slick ramp. But, now I’m not so sure. We never have any trouble pulling back out loaded.

Should my rear brakes be engaging on the car, before the front locks? They don’t seem to be.

Something else I noticed this weekend (wife’s car, I never drive it… she’s also the designated trailer operator), is that even driving it without a load, the front brakes always seem to be reacting with what I have come to associate with anti-lock braking. Going down a hill and feathering the brakes seems to result in front brake surges, makes the whole car shake.

Related? Any thoughts from those more automotive than me?

Thanks!

 

[sunbyrned]

I’m not an automotive guy either but I wonder if it would help if you were in neutral while going down the ramp. My boat wants to pull my Armada. I just started trying the neutral thing based on a suggestion. It seems more manageable to me in terms of less pull. Just going to add this to the conversation to see how someone might respond.

 

[feziwig]

Might want to get the rear brakes checked out.
also, if your trailer is too tongue heavy, could be levering the front and getting less weight on the wheels. With the longer wheelbase of the Yukon xl, could be whyit affects that and not the Tahoe.

 

[Julian]

Have you tried using the parking brake?

 

[dgfreeze]

I’d be suspicious that your rear brakes aren’t working, or doing so poorly. I believe a rough number is 60/40 front/back, so if you’re losing those rear brakes, it’ll quickly show up backing a boat trailer down a ramp. I’d have to look at where the extra length is put on a Yukon XL vs a Tahoe, but generally the longer vehicle wins that battle, unless hitch overhang is quite significant on the XL.

 

[BigAbe75]

I’d be suspicious that your rear brakes aren’t working, or doing so poorly. I believe a rough number is 60/40 front/back, so if you’re losing those rear brakes, it’ll quickly show up backing a boat trailer down a ramp. I’d have to look at where the extra length is put on a Yukon XL vs a Tahoe, but generally the longer vehicle wins that battle, unless hitch overhang is quite significant on the XL.

I was thinking that too. The longer wheelbase seems to do everything else better. Lol

I haven’t actually weighed the tongue, but I did move the boat back 6” on the trailer last year and the Tahoe definitely appreciated that adjustment.

 

[BigAbe75]

I’m not an automotive guy either but I wonder if it would help if you were in neutral while going down the ramp. My boat wants to pull my Armada. I just started trying the neutral thing based on a suggestion. It seems more manageable to me in terms of less pull. Just going to add this to the conversation to see how someone might respond.

I told her to let it roll a bit, because once it starts sliding, turning does no good. But, that’s counter intuitive when you’re not going the way you want to go.

 

[BigAbe75]

Have you tried using the parking brake?

Have not tried that.

 

[BigAbe75]

I’m thinking I better take it into a brake shop soon. We just had the fronts changed in the last few months. But, at the time they said the rear was ok. But maybe it’s a functionality thing vs worn pads.

 

[dgfreeze]

Is it 4X4? And if so, is it an “on demand” system only, or do you have a selector? What I’m getting at is this: if it’s a true 4X4, then having it in 4WD (especially 4WD LOW) should also work with braking. A lot of the newer on demand systems won’t work like that.

 

[BigAbe75]

Is it 4X4? And if so, is it an “on demand” system only, or do you have a selector? What I’m getting at is this: if it’s a true 4X4, then having it in 4WD (especially 4WD LOW) should also work with braking. A lot of the newer on demand systems won’t work like that.

It is. I usually drive it in 2wd. But at the ramp ask her to switch to AWD. I do have 4H and 4L options. We can try that next time.

 

[dgfreeze]

It is. I usually drive it in 2wd. But at the ramp ask her to switch to AWD. I do have 4H and 4L options. We can try that next time.

Yes, If you don’t get anything figured out/fixed before the next time you go, just drop it down into 4L before backing down the ramp. It should force the rear to brake equal to the front, but just beware it’s a much lower gear, so it requires more brakes to stop.

 

[2kwik4u]

Yes, If you don’t get anything figured out/fixed before the next time you go, just drop it down into 4L before backing down the ramp. It should force the rear to brake equal to the front, but just beware it’s a much lower gear, so it requires more brakes to stop.

Don't use 4L. Those cases like to bind on pavement and you're liable to get stuck. Just use 4H, it'll still lock the front/rear together, but has a VERY low chance of binding in place.

@BigAbe75 you definitely have something awry with those rear brakes. I can help walk you through them if you want to tackle it.

 

[BigAbe75]

@BigAbe75 you definitely have something awry with those rear brakes. I can help walk you through them if you want to tackle it.

@2kwik4u I’m just not quite that “handy”. (Or, don’t want to be) Lol

I’ll see if I can find a shop to help me. Since my dealer at home told me the pads look fine when they worked on the front, I’m feeling like it’s something more complicated. If I could get them to drive it, I think someone that knows more than me could diagnose that surge feeling pretty quick. Maybe it’s related…

 

[Sbrown]

The surging or shaking feeling your getting is probably not ABS, its more likely warped rotors. If the back are warped, the shaking will feel like its coming through the seat. If its front, it'll feel like the steering wheel is shaking. ABS application feels like a very fast vibration only in the brake pedal and is usually accompanied by the hum sound of the ABS pump motor.

 

[BigAbe75]

The surging or shaking feeling your getting is probably not ABS, its more likely warped rotors. If the back are warped, the shaking will feel like its coming through the seat. If its front, it'll feel like the steering wheel is shaking. ABS application feels like a very fast vibration only in the brake pedal and is usually accompanied by the hum sound of the ABS pump motor.

Ok, just talked to my wife. She corrected me (not a huge surprise). It was the rear brakes that were just replaced. And it was all new rotors and everything.

Yes, it’s the wheel shaking. Feeling like I better get the front end checked out soon.

 

[rbarthur21]

Is this just when backing the trailer down? Do you still have the trailer plugged into the truck or have the brake lockout key in when backing down the ramp?

 

[BigAbe75]

Is this just when backing the trailer down? Do you still have the trailer plugged into the truck or have the brake lockout key in when backing down the ramp?

Front end shakes / surges when braking with just normal driving - no trailer.

Only noticing the front lock up when backing down at the ramp. No, not using the lockout key (never have)

 

[rbarthur21]

Front end shakes / surges when braking with just normal driving - no trailer.

Only noticing the front lock up when backing down at the ramp. No, not using the lockout key (never have)

I only ask because the trailer brakes will engage when backing if you don’t have the trailer plugged in or the brake lockout key in. It creates a weird shaking feeling. I made this mistake at the ramp once.

 

[BigAbe75]

I only ask because the trailer brakes will engage when backing if you don’t have the trailer plugged in or the brake lockout key in. It creates a weird shaking feeling. I made this mistake at the ramp once.

I always leave the trailer plugged in. I think this is a different phenomenon.