Brakes locking

[trumpetguy]

2007 Classic with Hydraulic brakes. This trailer is new to us.

I towed it home from the dealer about 200 miles and brakes worked fine. We set out for a trip to North Georgia this past Monday and the first time I applied brakes the trailer locked up. The only way to unlock was to dial the ITB down to zero.

Four trips to the Ram dealer in two days and they told me the Ram ITB cannot work with Hydraulic brakes and I should buy an after market controller. I bought a Primas controller plus the adapter cable to plug into the Ram ITB socket and now I get the same result. Brakes lock up.

My mobile RV tech is convinced the problem lies in the trucks computer and he wants to unplug the Primus from the truck and re wire it directly to the seven way plug.

My logic says the problem is with the trailer because the Ram ITB did fine on our trip home from the dealership. But what should cause the brakes to remain locked after lifting my foot off the brake pedal?

I can hear the hydraulic pump operating and it stops when I release the brake pedal.

Has anyone else experienced this problem. It has ruined our week and I am really stressed out.

[Bill M.]

I do not have hydraulic brakes on my trailer. But...could it be the brakes themselves? I have heard that the slides on the calipers can bind if the brakes are not used often enough or lubed often enough.

[GCinSC2]

Originally Posted by Bill M.

I do not have hydraulic brakes on my trailer. But...could it be the brakes themselves? I have heard that the slides on the calipers can bind if the brakes are not used often enough or lubed often enough.

Above is good advice.

I own a 2007 with disc brakes. But the calipers are fixed not floating like most automotive calipers. These are 4 piston / brake caliper assemblies.

Pull a wheel that is accused of locking up. The pads are retained by a clip and pin. Pull clip then pin remove pads, clean anchor points and apply small amount of caliper grease. Pads are pretty thick I can measure spare at home if you’d like a reference dimension. Repeat on all wheels.

At the same time check bearings by rocking wheel top bottom and observe movement. Dexter has specs.

Ok those are the easy ones and this is the ocrap moment inspection.

When pads are pulled look at dust seals. All torn up? Not good.

When dust seals are damaged water can get in and steel piston can rust to cast iron caliper.

Dexter sells seal kits it can be done if semi skilled and patient.

I have done fairly extensive work on my brakes including seal R&R mostly due to planetary misalignment not bad brake design.

Gary

[Al and Missy]

Gary and I were typing at the same time. What he said. He has had and solved this problem.



Presuming you set the controller(s) for electric over hydraulic brakes, there can be many possible causes.

1. Some ITBC are not compatible with disc brakes. A typical fix is to wire an electric brake magnet across the brake line so that the controller sees more current drain.
2. Maybe corrosion or trash in the brake lines or calipers. Bleed the brakes. If they are Dexter dual piston calipers they have two bleed screws, one on the front cylinder and one on the rear and are hard to bleed completely due to the crossover tube from one side of the caliper to the other. Air can get in the top of the rear cylinder and not be forced out the lower bleed screw.
3. Hydraulic actuator may have failed and is not releasing the pressure when you take your foot off of the pedal.
4. Corrosion on the calipers. Pop the wheels, pull the pads and check the grooves the pads slide in for corrosion. Clean and lubricate. Inspect the rubber boots on the pistons for tears and the pistons for corrosion. Disc brake systems typically have multiple metals in the calipers. If water is allowed to enter, there will be corrosion. If a piston boot tears, there can be corrosion where the piston exits the caliper.
5. Last thing I can think of is a bad controller, but you have already mitigated that with a replacement.


Al

[GCinSC2]

Al has become a recent convert to disc brakes and has seen the light reporting how well his works.

We might as well add that the 2007 was subject to two brake recalls. Yours may have already had them addressed but one was for a specific actuator failure and the other for installing longer hoses to prevent linking and hose failure or brake dragging.

With the VIN contact AS and ask if recalls have been performed.

But your brakes when tuned up and annual inspected are I think the strongest most capable brakes ever installed on an AS.

Also do not accept brake actuation delay as normal.

Gary

[Woosch]

We had a problem with the brakes intermittently engaging a number of years ago. First I would check the actuator. I think the original was Actibrake and if that is still in there I would replace regardless of wether it's the culprit. The brake controller was suspected in our case but it checked out ok. Additionally there was a recall on the disc brakes for the 2007. I don't recall exactly what is was for but it was a very quick inspection.

[trumpetguy]

Thanks all. I plan to have the brakes checked and will also contact AS about the recall. The problem of locking up occurs only when I use the slide switch on the Primus controller...not when I apply the truck brakes. We drove from Gulf Breeze, FL to North GA and the braking was satisfactory so either my truck has incredible brakes, or the Primus was doing its job and Proportioning the braking signal to the trailer. At any rate a trip to my RV dealer is in the immediate future.

[Julie-Bob]

Inform us of the fix

[trumpetguy]

J D Sanders Airstream in Alachua, FL kindly worked us in while we were on a trip to Anastasia State Park in St. Augustine. After much diagnostic effort it was determined that the hydraulic pump was faulty. $1300.00 to replace and they had one in stock. When the service manager went to pull the pump from parts the manager said “this may be covered by a recall”. So they did the hole drill to see if fluid was leaking into the circuit board and hallelujah it was covered. So we have a new pump. Still no signal from the Primus brake controller and we had to get back on the road. At least I could activate the slide switch on the Primus which would do in an emergency but no signal when I stepped on the brakes.

So I did some more research and learned the Primus brake control does not work with hydraulic brakes. Solution...buy a Prodigy 2 control and program it for Electric over Hydraulic. Still no signal from the brakes. Called Prodigy and was told the controller needs 9 volts from the brake signal so something must be wrong with the wiring. Drove the truck to a local trailer and hitch company (should have started there rather than the RV guy). They unhooked the hardwire used by the RV guy and installed the vehicle specific wire harness/plug provided by Prodigy. Back to the house to test the brakes and still nothing when I pressed the brake pedal. By this time I am thinking I have to get a new truck. Last call is to Dexter axle. Within 60 seconds the tech told me exactly what was going on. There was nothing wrong with any of the hardware. The Prodigy 2 is a Proportional brake controller with an Accelerometer, meaning it works only when moving. I hitched up the trailer and rolled a bit down the driveway. Bingo, brakes work.

Lessons learned...
Don’t use a mobile RV guy
Take your rig to experts.
Research before buying a product.

[GCinSC2]

Replaced under recall, GO BUY LOTTERY TICKETS!

That's great news.

Yes, learn how YOUR system works and please consider an IR temp gun you can learn alot about how they (brakes) and other components are working. Great trouble shooting tool.

Safe travels.

Gary

[GCinSC2]

Did they check on the brake hose recall too? That's a big plus for safety and easier bleeding of the brakes.

[trumpetguy]

Originally Posted by GCinSC2

Did they check on the brake hose recall too? That's a big plus for safety and easier bleeding of the brakes.

They did check the lines and were going to replace them under recall but I declined due to time issues. I am having this done starting tomorrow at Foley RV in Gulfport, MS along with some body work to replace a dented panel.

[GCinSC2]

Good, get it taken care of. It really helps with bleeding them also because it allows cracking the line on inboard side of caliper and outer via bleed screw.

[trumpetguy]

We dropped our Classic at Foley Airstream in Gulfport,MS for some body work and other items including the recall. What a great dealership. They act as if they actually appreciate your business. I’m hoping the repairs are equal to their attitude.