Jump to content

truck brakes


GlennWest

Recommended Posts

9 hours ago, Scrap said:

 

Bobtail proportioning isn't something to be taken lightly.  That's why there is a big fat red warning sticker on the dash.  It is only OK on a bare rear end tractor that is looking for an air braked trailer.  It was never done on a truck that carries something and if you "build out" a tractor that adds more weight to the rear then it needs to be removed.  If you've got an electric trailer, plug your red line, and rely on memory to push in the red valve you are playing with fire.  It really should be interlocked.

 

 

 

 

What would be involved in changing from a proportional setup to interlocked on a Volvo 770?

 

Link to comment
Share on other sites

I did an experiment on my truck a couple years ago, to investigate if there was any difference in braking with the trailer air system charged.  I put my gladhand / air chuck female on the red line, plugged gladhand on the blue.  Road test with trailer on (~50K lbs total) showed no difference in brake feel.

On the trailer brakes not working thing, I do the tug test after every hitch up and would notice a trailer brake problem before I took off.

Also, after a stop where I was away from the truck, or shut it down, I do the normal walk around inspection before returning to the road, then when I take off, I hit the trailer brake lever to verify brakes working.

I still got the big 3" wide electric drums on the Teton.  They work great but get very little use.  I keep them adjusted. Real easy to do after I installed two more hydraulic cylinders that gives me 6 point leveling and the ability to lift the whole trailer off the tires.

If you still got 3 axles on your truck, you should be good on braking. Just make sure the trailer is straight behind you when you do that panic stop :D

   

 

 

2009 Volvo 780 D16 535hp 1850 ft-lbs I shift 3.36

Thermo King Tripac APU

DIY Bed and Frame Extension

ET Hitch, Stellar EC2000, EcoGen 6K

2002 F350 CC Dually w/ Lance 1181

2012 Mini Cooper S

2007 Teton Royal Freedom

 

" The only place you will find success before work is the dictionary "

Truck 100K.jpg

Link to comment
Share on other sites

9 minutes ago, Mastercraft said:

I did an experiment on my truck a couple years ago, to investigate if there was any difference in braking with the trailer air system charged.  I put my gladhand / air chuck female on the red line, plugged gladhand on the blue.  Road test with trailer on (~50K lbs total) showed no difference in brake feel.

On the trailer brakes not working thing, I do the tug test after every hitch up and would notice a trailer brake problem before I took off.

Also, after a stop where I was away from the truck, or shut it down, I do the normal walk around inspection before returning to the road, then when I take off, I hit the trailer brake lever to verify brakes working.

I still got the big 3" wide electric drums on the Teton.  They work great but get very little use.  I keep them adjusted. Real easy to do after I installed two more hydraulic cylinders that gives me 6 point leveling and the ability to lift the whole trailer off the tires.

If you still got 3 axles on your truck, you should be good on braking. Just make sure the trailer is straight behind you when you do that panic stop :D

   

Singled my truck.

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

1 hour ago, Scrap said:

It is still proportional, it is just that the trailer won't let you move until the red knob is in.  This is what we invented in a thread about it a few years ago.  I have no idea what it would take to get it in a Volvo though.

 

Got it, thanks.  That makes sense.  Unfortunately, it doesn't resolve the situation for my configuration where I have a several thousand pound bed, and often have something on it, with no trailer.  I really can't drive the truck safely/comfortably, even with no trailer and nothing on the bed, without the trailer release knob pushed in.  So, maybe in my case, I just need to bypass that valve so that the main brake release always supplies air to the trailer side?  It's not high on my to do list, but maybe I'll investigate it further sometime.

 

Link to comment
Share on other sites

Oh, for that you just have to take the control line on the BPR valve and plumb it direct to tank.  Then it is defeated.  Officially I have to recommend changing out the valve to a real relay instead, but if a plumbing change gets you to do it sooner...... ;)

Link to comment
Share on other sites

On 11/28/2017 at 11:11 AM, Mark and Dale Bruss said:

You have to take some statements with a grain of salt, like I get 10 mpg towing the trailer".

 

Actually, I've gotten that much verified by filling, not computer. But it does not happen often and it was only with this new truck, or going back to my lighter trailer with my ISM. Then I routinely did get in the 10's....But the trailer was only 16K lbs. However, I'm impressed with this truck....pulling my 28K plus trailer at 67 mph I actually got in the 10's. Once.

Jack & Danielle Mayer #60376 Lifetime Member
Living on the road since 2000

PLEASE no PM's. Email me. jackdanmayer AT gmail
2016 DRV Houston 44' 5er (we still have it)
2022 New Horizons 43' 5er
2016 Itasca 27N 28' motorhome 
2019 Volvo 860, D13 455/1850, 236" wb, I-Shift, battery-based APU
No truck at the moment - we use one of our demo units
2016 smart Passion, piggyback on the truck
-------------------------------------------------------------------------
See our website for info on New Horizons 5th wheels, HDTs as tow vehicles, communications on the road, and use of solar power
www.jackdanmayer.com
Principal in RVH Lifestyles. RVH-Lifestyles.com

Link to comment
Share on other sites

8 minutes ago, Mntom said:

Geez, my LGT got 11 to 12 mpg pulling my 28' trailer and 10 to 11 mpg with my 38' trailer at 65 mph.

Chevy got like 5-6 towing the Teton, 21k

2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1

Link to comment
Share on other sites

My LGT gets near 20 empty, but about 7 pulling the 5er.  That's a manual 12 valve Cummins tuned to about 225 hp.

Av8r3400
2012 Volvo VNL 730 D13 iShift & 2021 Grand Design Momentum 397TH

TEq81qV.jpg

I'd rather die trying to live - Than live trying not to die.   -Leonard Perry

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...