cheby pulling beast

[workgoats]

My daughter, Bruce's wife, Georgia's mother, recently had her suburban totaled.  She picked up her replacement today.  Ernest will be drooling...

2002 3/4 ton, 4x4 GMC suburban (Yukon XL) with a 8.1 L engine, Allison tranny and 373 gears with a rear locker.

She should not have problem getting the horse to the rodeos but she may have a problem finding enough gasoline...

[rjtx667]

how many gallons per mile is that? 

[workgoats]

It runs 2100 rpm at 70 miles per hour.  Should get 8 to 10 in town and previous owner said he got about 12 to 13 on the highway pulling a large boat.

[rjtx667]

thats not that bad... the mexico ramcharger gets about 10 pulling the trail truck... the cummins gets about 14.

Granted thats also pulling at 65-70 and accelerating uphill 

[workgoats]

She's about to hook up the trailer for the first time for Georgia to go to a riding lesson. 

With 450 ft# of torque, I suspect she will be able to accelerate any time she wants to as well.

[KeystoneSmooth]

How did the pull go?

[workgoats]

Riding lesson was only a couple of miles from our pasture.  They were supposed to make a play day out of town but we've had so much wet weather the horse has an abscess on his foot and couldn't go.

We do have it riding level and it looks good.  Does that count?

[KeystoneSmooth]

Any news on the 8.1?

[workgoats]

We finally got to do a road trip, pulling one horse to a rodeo about 2 hours away from home.  Parking was in muddy parking lot.  Tracy got to put it in 4x4 for the first time but it wasn't bad enough to spin any tires. 

It has no problems pulling one horse at any speed.  I put a serpentine belt on it.  Just like any GM product.  The plug and play brake controller is not getting power to the brakes.  I'll have to do something about that.  It does have an automatic leveling system.  It seems to work very well.

[workgoats]

BTW, we didn't do any mileage tests on this run but it doesn't seem to use any more gasoline at 65, pulling the trailer, than the older suburban with the 5.3 engine.  The 8.1 has 373 gears and I'm guessing the old one had 355 or there abouts.

[workgoats]

Driving down the road the other day the brakes begin to lock up on the beast until they were so tight that the 8.1 engine would not move it.

All four wheels were locked and it wouldn't move till she called me and I had to open a bleeder valve on both the front and the back.  One GMC forum said they had had this problem with a defective master cylinder.  Parts store says no way.  Only thing it can be is the hydroboost. 

I replaced the master cylinder and solved the problem.

The only time this has ever happened to me was with a 71 Fiat roadster.  In freezing weather the brakes locked.  That was because it had too much water in the brake fluid and froze.

[rjtx667]

thats no fun, its too cold to be working on trucks right now... I have a oil sensor that is going out on the durango I am putting off on replacing