Willie B
Senior Member
I have a 1990 GMC Top KIck 10.4 liter Cat 3208. Allison trans. Case 580 Super N backhoe on the trailer.
Route 11/30 from Peru is seven miles to where it meets Route 7. I came down the mountain in third gear allowing it to get up to 40 MPH before helping with brakes. Some hills are 8% grade, but others are gentle grade or flat. The onramp to route 7 North is very steep & at lowest point is joined by the onramp from 11/30 West. I came on the brakes hard entering the onramp & little or nothing happened. I realized my foot was to the floor! pulled it into second in desperation. The inevitable was about to happen!
An Old Dominion tractor trailer was feet from entering the intersection & he piled on his brakes. By some miracle, I made the curve & he didn't enter the ramp. Ramp turned uphill, & I looked at air pressure, 100 LBS. Electric trailer brakes were working fine, but not set on highest setting.
I got home, tried the brakes, as usual, at low speed they are too good, they'd put you through the windshield if you press too hard. All is new within 5000 miles. New tanks, lines, mysterious control devices, cans, shoes, rear drums this spring.
My theories were too hot intermittently using them down the mountain, or I used up the air, but immediately there was 100 psi. I haven't figured out what went wrong!
Route 11/30 from Peru is seven miles to where it meets Route 7. I came down the mountain in third gear allowing it to get up to 40 MPH before helping with brakes. Some hills are 8% grade, but others are gentle grade or flat. The onramp to route 7 North is very steep & at lowest point is joined by the onramp from 11/30 West. I came on the brakes hard entering the onramp & little or nothing happened. I realized my foot was to the floor! pulled it into second in desperation. The inevitable was about to happen!
An Old Dominion tractor trailer was feet from entering the intersection & he piled on his brakes. By some miracle, I made the curve & he didn't enter the ramp. Ramp turned uphill, & I looked at air pressure, 100 LBS. Electric trailer brakes were working fine, but not set on highest setting.
I got home, tried the brakes, as usual, at low speed they are too good, they'd put you through the windshield if you press too hard. All is new within 5000 miles. New tanks, lines, mysterious control devices, cans, shoes, rear drums this spring.
My theories were too hot intermittently using them down the mountain, or I used up the air, but immediately there was 100 psi. I haven't figured out what went wrong!