My brakes suck

[MaxTow]

Originally Posted by ROBERTSUNRUS

Hi, of course you already know this, but new brakes need time and miles to seat in. Also your drums should have been machined too. My original brakes are still good, but after several years of use and a bearing repack, I had my drums machined on both the lining and magnet surfaces. Both need a better contact point.

I think this is the next step...the brakes appear to be getting a little stronger with more use - but still not what I would like.

[MaxTow]

Originally Posted by AirsDream

A few comments here, trying to help you figure out the reasons for inadequate braking. First, generally speaking, going UPHILL in a lower than needed gear won't heat up your transmission nearly as much as in a too high a gear.

Typo on my part. I found Toy/Haul mode was selecting too high a gear on some of the steep climbs, so fell back to manual selection of the gear. By selecting a lower gear, the transmission temperatures were better regulated.

My first trip with the rig into really big mountains. It was only on a couple of occasions where the temperatures climbed out of nominal. The climb out of death valley CA at 46C (115F) was memorable. I liked the sign that recommended turning off the AC for the next 20 miles.

I followed the suggestion...

[HiHoAgRV]

Originally Posted by MaxTow

I think this is the next step...the brakes appear to be getting a little stronger with more use - but still not what I would like.

I noticed the same thing on my '63 this last week. After a few thousand miles, they are really grabbing now. I suspect they would lock on wet roads. I'm guessing the pads and drums are starting to seat profiles.

The difference is so noticeable that simply tapping the pedal while backing up causes a slam stop.

[MaxTow]

Originally Posted by AirsDream

Second, have you checked your trailer brakes on a smooth dirt road? An old pro once told me this: a good, hard packed dirt road will produce a coefficient of friction about 80% that of good pavement. So, he argued, to test and adjust your trailer brakes, take the loaded rig down a good dirt road at about 35 mph and apply ONLY trailer braking force by using the "squeeze handle / slider" (or whatever it's called) on your brake controller, eventually applying full trailer braking force. By slowly increasing the amount of "gain" produced by the controller, you should be able to get to the point where the trailer's brakes will begin to lock and the tires to slide. The notion is that this means that on pavement, you should come just short of locking the brakes ... and so will not risk losing control in a max-braking scenario. I do this religiously every season, just to make sure that my OEM brake controller is "talking" correctly to the trailer brakes. Give this a try before you do anything else. If you can't lock the brakes on a dirt road at moderate speed, even with the gain control all the way up, you may not have enough braking force. (Be ready to release the brakes IMMEDIATELY, of course, if you do get lockup, so the trailer doesn't start to slide off course!)

I've heard mixed reviews on getting the wheels on the larger airstreams to lock up. Ours is the 30' Bunk. GVWR is 8400lbs. On this trip is was in the mid 7000s most of the time.

I've not tried on a dirt road. I'll give that a whirl as I continue to tune the system.

[MaxTow]

Originally Posted by AirsDream

Third, just because self-adjusting brakes are installed doesn't say anything about the state of adjustment right after they are installed. You need to hand-adjust the brakes just after installation ... I've personally never seen new axles (self-sdjusting or not) that came from the factory correctly adjusted. Once set up, the self-adjusters will HELP keep the brakes properly set for no-drag, ready-to-engage clearance, but they still want regular manual attention. And remember: they only adjust when you back up and apply the brakes relatively firmly. (We trailer folk tend not to back up too much and to apply the brakes gently, lest all that cupboard "stuff" move around and cause a big mess!)

When installing I had to loosen (pull in) the pads so that the hubs would slip over the mechanism. Once installed I then went through the standard process for adjusting...turn the star wheel until the brakes are locked, then back off about 8 to 10 clicks.

I readjusted again the next day after towing about 400 miles.

The brakes are advertised by Dexter to self adjust when going forward or backward.

[MaxTow]

Originally Posted by AirsDream

Then too, if you intend to do a lot of mountain towing, you might want to consider a 3/4 ton tow vehicle. They have MUCH larger brake rotors, etc. and do a much better job of dissipating any extra kinetic energy that might build up if your speed starts to creep up. And remember that the energy you have to dissipate goes up with the SQUARE of your speed ... so increasing your speed from twenty miles an hour to forty causes the energy to go up by a factor of four.

Thanks for all the great information. I would say that my expectations of performance (speed) for going uphill and downhill needed to be adjusted as we travelled through the mountains.

I had to learn to watch the gauges more carefully going uphill -

And slow down on the descents.

Very slow down from Sylvan Pass leaving Yellowstone,
Very Very slow up and over Towne Pass out of Death Valley

And even though it was relatively cool, had to watch the transmission temp over Powder River Pass in SD (9666 ft)

I certainly cannot complain about the brakes on my F150. While they were doing more than what I would characterize as their fair share of the braking, then performed well. I had them checked along the way to make sure everything was in good shape and that there was plenty of pad life left.

Of course you want the 3/4ton brakes to be larger - they have a heavier truck to stop.

I am very intrigued however with better engine breaking from a diesel.

[switz]

The mountain roads were an inputus for me to install oil temperature gages in both the front and rear differential as well as the transmission. I also installed the largest capacity differential covers with cooling fins. I monitor EGT, the inches of boost and the fuel rail pressure along with the standard gages of water temperature, engine oil pressure and battery charging. The fuel gage is "confused" by the 56 gallon vs stock 34 gallon diesel fuel tank.

Coming back through Salt River Canyon (7% down slope for five miles) with a 5,000 pound cargo trailer attached, the truck brakes were not needed because of the diesel engine braking and keeping the speed down close to the "suggested" limit.

[gmw photos]

Originally Posted by switz

The mountain roads were an inputus for me to install oil temperature gages in both the front and rear differential as well as the transmission. I also installed the largest capacity differential covers with cooling fins. I monitor EGT, the inches of boost and the fuel rail pressure along with the standard gages of water temperature, engine oil pressure and battery charging. The fuel gage is "confused" by the 56 gallon vs stock 34 gallon diesel fuel tank.

Coming back through Salt River Canyon (7% down slope for five miles) with a 5,000 pound cargo trailer attached, the truck brakes were not needed because of the diesel engine braking and keeping the speed down close to the "suggested" limit.

Ok, so enquiring minds want to know what the front and rear diff oil temps typically run on a good pull.

[switz]

Front differential stays cool (140) as there is no load. The transmission and rear differential have been running around 155 degrees each in the cooler weather.

We have a hard pull scheduled in the mountains in September coming out of Phoenix headed for the Grand Canyon vicinity and there is a good long climb that will be interesting to watch.