Disc brake lag

[Don.44]

The master cylinder on the trailer is an Actibrake .
Don

[Don.44]

Just started our trip to Fl and what a\ nightmare I am having with the delay in the brake system Hydraulic brakes should be surge brakes This disc system is so dangerous

[Dwight]

When did you last bleed your lines of air? Air doesn't compress very well and that may be some of the problem...

[nvestysly]

Originally Posted by Don.44

Just started our trip to Fl and what a\ nightmare I am having with the delay in the brake system Hydraulic brakes should be surge brakes This disc system is so dangerous

Bleeding out trapped air (as mentioned by Dwight) is critical to proper operation. A good connection at the 7-way connector is equally important as is the proper brake controller. Also check the ground wire. Faulty grounds can cause lots of problems.

For the ActiBrake to work you need an "electronic" brake controller. The brake controllers typically have several settings for different types of brakes and the amount of power you want delivered to the brakes. If your controller is set for electric brakes it will not control the hydraulic brakes properly.

I suggest a professional if you cannot figure out how to make them work properly. A good professional may be difficult to find. Several RV dealers/service shops told me they don't work on hydraulic brakes. I found the smaller shops were actually better informed as they see a wide variety of rigs and they were willing to take time to talk through the issues. Regardless, you want your brakes to work.

Lucius

[barts]

I'll echo the others - bleed the brakes. Repeatedly. Any extra compliance ('springiness') in the system between the actuator and the discs will cause delays.

There will be a irreducible minimum delay; it is perceptible but doesn't appear to cause any problems.

- Bart

[GCinSC2]

Don.44,

I'll echo the above comments and offer my latest thoughts.

How do you know when its fully bled or something else? Well, I think when its fully bled you'll be able to tell with resposive, comfortable reliability but a few other things contribute also.

I can't claim expert at this but I have put a lot into my brakes for various and often unrelated issues and about 2 weeks ago I just installed (I did it) two new rear calipers to cure (nope, not really cured yet, more to follow later) my last hot brake issue.

1. All components must be functioning correctly. My Actibrake was leaking I didn't know it. I chose to R&R with Carlisle I have a pic up of my Actibrake internals showing fluid carnage. If yours was part or the recall, I'd keep an eye on the drilled inspection port for evidence of weeping.

2. Sticking caliper pistons. The Dexter caliper is a cast iron body. The caliper pistons on my rig are steel. All components BEHIND the pressure seal are bathed in DOT 3 brake fluid, internal corrosion possible from DOT 3 absorbing moisture , might want to inspect your reservoir cap for integrity. This is also my new incentive for perodic bleeding to flush out old and replenish with new fluid. The piston that sticks out and makes contact with the pad goes thru a dust boot. This section of piston behind the dust boot but above primary seal is also in contact with about a 3/16" band of the raw cast iron caliper body and IMHO is subject to corrosion. This corrosion might hinder the brake application but I think the real corrosion issue is that it will not freely allow the piston to retract as it naturally does during brake release and it can hold brake in an applied position and causes a ton of heat, burned pads, rotor and a reduction in braking effiecency/effectiveness. Also if your rotors have runout from previous extreme heat, they might be warped a bit and the runout could cause the pistons to be pushed back in farther than normal, also requires more time to push pads out to make rotor contact = delay.

3. I would look thru the wheels and get a quick visual of the pad condition and you might even be able to see sections of the dust boot. If the dust boot is torn, brittle or gone, time for caliper rebuilding possibly.

4. Back to bleeding, how do you know when it is bled. I'm thinking about investigating this further, but I took a tech call at work last week and the shop owner was describing a brake pressure gage that taps into the bleed screw port, he stated it has several ways to read and interpret the readings, I need to reseach further. But the PSI should be common throughout the system if all hoses are functioning AOK. I'll report back after I find out if the reading might show a ramp up that would indicate the pressence of air in the lines.

In the future I will not be washing my wheels and flushing off the brakes in the process and then parking the rig w/o taking it out for a drive to fully dry off the rotors, pads and calipers befor parking.

I have stated before, low mileage rookie, but with more wrenching years that lots of veteran AS'ers, My rig 30' S/O (heavier AS) with MaxBrake, Carlisle and correctly functioning calipers is very comfortable. I'm not feeling a significant delay, the brakes are coordinated to my TV and I know they are capable of hard braking, I left a short strip on my last brake test drive.

I also now feel that I have a decent ideal of what I as an owner need to be thinking about to keep my disc brakes ready and able.

Don.44 I hope you can find your gremlin(s).

Gary

[dznf0g]

"I know they are capable of hard braking, I left a short strip on my last brake test drive."

Gary,
I, Unfortunately, can attest to this. Right after I got my new 16" tires and wheels, I somehow, sometime, unknowingly must have adjusted my Heyes controller to 90% apply max. At a 55MPH road a stop light turned yellow. Rig stopped on a DIME!!!! Unfortunately, when the weight all shifted forward, my rear AS brakes locked up. Flat spotted the new tires! Not too bad though, they'll heal back in with some miles.

I think the disc brake system works great. AS just had some poor vendor choices relative to actuator and perhaps rubber brake hoses. This "tarnished" the image of the disc system and they changed back. (probably reduced cost was a factor too)

I, for one, like the disc setup, and am glad I have them.

[barts]

Originally Posted by dznf0g

I, for one, like the disc setup, and am glad I have them.

Hear hear.

The Tin Pickle's discs are of course aftermarket; when we replaced the axles we splurged on discs as well; Inland RV sells the Kodiak kits & actuators.

Result: this is by far the best stopping trailer I've ever pulled. Really. I've had a few hard stops due to people not estimating our speed correctly (the longer the vehicle, the more slowly it appears to travel); the truck and trailer just stop. Hard if you want. Remember to pack the trailer as if it was going to descend a nearly 45 degree slope, because that's where the force vectors point on hard braking. The nice Michelins we have on the Tin Pickle (and truck) don't hurt either.

I may eventually go to a Max Brake style controller so I can avoid the eccentricities of the controller trying to guess how hard I'm pushing on the brake pedal, but that's merely an annoyance in hilly stop and go traffic.

- Bart

[GCinSC2]

dznf0g,

Sorry if I might not seem to be playing my last card, I have more in mind to do, just haven't done it yet so don't want to say what hasn't been done.

My trailer has new 5,000 lb axles, I recently had a problem, more research etc. etc. I think if you research and look at caliper kits you will find that our disc brakes are actually rated up to 6,000 lb axles. Just installed and from the label "K71-636-00 Caliper replacement kit for Dexter 6K disc brakes left or right hand" Our axle rating is determined by cord length (right?) for weight capacity but brake hardware is capable of higher ratings. So I have a ~9,000 Lb trailer with brakes rated up to 12,000 lbs.

Gary

[dznf0g]

Originally Posted by GCinSC2

dznf0g,

Sorry if I might not seem to be playing my last card, I have more in mind to do, just haven't done it yet so don't want to say what hasn't been done.

My trailer has new 5,000 lb axles, I recently had a problem, more research etc. etc. I think if you research and look at caliper kits you will find that our disc brakes are actually rated up to 6,000 lb axles. Just installed and from the label "K71-636-00 Caliper replacement kit for Dexter 6K disc brakes left or right hand" Our axle rating is determined by cord length (right?) for weight capacity but brake hardware is capable of higher ratings. So I have a ~9,000 Lb trailer with brakes rated up to 12,000 lbs.

Gary

Not sure what you mean by cord length, but I have my suspesion that all the 5000# axles supplied by Dexter are actually 6000# axles. Here's why I say that:

There is no 5000# axles on Dexter's website.

When I called Dexter on some subject about the axle, I told them I had 5000# Dexter axles on my AS. They said they were 6000#. I said no, the literature says 5000# and there is a white handwritten 5000# next to the Dexter label. They had me shoot a pic of the label and give them my VIN. They called back and said AS had rated my axles at 5000#, but parts for Dexter's 6000# axle are the correct replacement parts. I believe AS has derated the axle spec so WE WOULDN'T overload other AS systems to the point of potential failure. Published axle ratings in the automotive world (and I suspect the trailer world too) are set to the weakest link in the tire, wheel, spring, axle, frame (Monocoque shell, in the case of AS) system.

All that being said, PLEASE don't apply more load on your axles than specified by AS.

[GCinSC2]

I thought that the rating of a axle was tuned by the length of the rubber cords frozen and inserted into the axle housing at assembly, longer cords requires more of a load to rotate, equals spring "rate". If I missed this one, please correct this info. The axle on my trailer is Dexter 58593 and from the a Dexter spec sheet it has 5000RC rated capacity. My data tag on the street front corner states GAWR Each Axle 5,000 lbs. The 2007 Airstream Classic Parts Book lists 410875-17, Axle 5000# 31', 30', 30'S/O.

Agreed, do not overload. I have never even carried any type of water load with my rig.

I just hope Don.44 can get some relief for his in-route braking situation.

[dznf0g]

Originally Posted by GCinSC2

I thought that the rating of a axle was tuned by the length of the rubber cords frozen and inserted into the axle housing at assembly, longer cords requires more of a load to rotate, equals spring "rate". If I missed this one, please correct this info. The axle on my trailer is Dexter 58593 and from the a Dexter spec sheet it has 5000RC rated capacity. My data tag on the street front corner states GAWR Each Axle 5,000 lbs. The 2007 Airstream Classic Parts Book lists 410875-17, Axle 5000# 31', 30', 30'S/O.

Agreed, do not overload. I have never even carried any type of water load with my rig.

I just hope Don.44 can get some relief for his in-route braking situation.

Oh, cord = spring rubbers, OK. I have no idea what limits the ratings specifically ON the axle itself.

[dznf0g]

Originally Posted by GCinSC2

I thought that the rating of a axle was tuned by the length of the rubber cords frozen and inserted into the axle housing at assembly, longer cords requires more of a load to rotate, equals spring "rate". If I missed this one, please correct this info. The axle on my trailer is Dexter 58593 and from the a Dexter spec sheet it has 5000RC rated capacity. My data tag on the street front corner states GAWR Each Axle 5,000 lbs. The 2007 Airstream Classic Parts Book lists 410875-17, Axle 5000# 31', 30', 30'S/O.

Agreed, do not overload. I have never even carried any type of water load with my rig.

I just hope Don.44 can get some relief for his in-route braking situation.

I understand, let me clarify: here's the label from my axle (same as yours?)



I have NO DOUBT that a Dexter spec sheet for that specific axle part number, AND all AS material will refer to it as 5000#. Many times when a manufacturer gets a component from a supplier, it will have a unique part # and specing to match the manufacturers needs and to ensure that only that part # goes to AS with those specs. Many times the only difference between those parts and the off the shelf part, is the part#.

I you go online to Dexter and look for their axles, and more importantly, their replacement parts for disc brakes, you will find only parts for 3500#,6000#,8000# and 9000-15000# axles.

No parts for a 5000# axle available? NO, I was told by Dexter use the 6000# components. (first I was told there was no 5000# axle)

SO, the question remains, is there some difference, physically, between an off the shelf 6000# Dexter axle and an AS sourced 58593? Or is the difference only a logistical, specing and labeling issue.

I have no idea.....and it really doesn't matter as (in my case, even at 5000# per axle, for a 10,000 GVWR AS) I'm overloaded...unless I have zero#s on the tongue....that'd be interesting, wouldn't it?

Minimally, I should have no more than 4500# per axle with 1000# tongue, with a 10,000# GVWR trailer.

But from a parts ordering standpoint I was told, right or wrong, to order the 6000# part #s.

I don't know if I were to walk into a Dexter Distributor and asked for pads for my 58593 if the listing would be found.

[GCinSC2]

dfnzog,

I have no idea if it is a logistic and lable on the axles. My axle label, same part number as yours.


Gary

[Don.44]

We made it to our destination 1750 miles Not a fun trip with the brakes working like they did. I stopped at A FL dealer and described my issue . They are offering a free inspection of the Activator . If it is found to be defective they will replace it (NC) but of course there is a catch. I may have to leave it with them for up to 3 weeks . I was told that the new Air Streams have gone back to using electric brakes I wish I had them on mine as my old Air Stream had them and they never gave me any trouble like the disc brakes have.

[crispyboy]

Don.44 - I'll trade you my working electric brakes for your non-working disk brakes

Dexter Axles - I have changed out two sets of Axles and have used Dexter both times.
From Dexter's information they have Torflex axles which are numbered 8 through 13. Each number corresponds with a range of weight the axle is designed for.
For example - My present trailer used a #11 axle. The range for this axle was 3600 - 6000 lbs. Dexter uses different size rubber rods in this axle for the weight specification. The axle I ordered also had a larger spindle, 12" brakes and the tube was larger than the original Henshen axle. The weight rating of the axle was increase a slight amount to get into this heavier made axle.

One way you could get some hints on the exact axle would be too measure the axle tube. The #11 axle is 3.03". A #12 axle is 3.5".

[GCinSC2]

Don.44,

Glad you made it safely, hopefully something will be determined and work it out.

crispyboy,

Interesting additional Dexter axle info.

Gary

[Inland RV Center, In]

Originally Posted by GCinSC2

I thought that the rating of a axle was tuned by the length of the rubber cords frozen and inserted into the axle housing at assembly, longer cords requires more of a load to rotate, equals spring "rate". If I missed this one, please correct this info. The axle on my trailer is Dexter 58593 and from the a Dexter spec sheet it has 5000RC rated capacity. My data tag on the street front corner states GAWR Each Axle 5,000 lbs. The 2007 Airstream Classic Parts Book lists 410875-17, Axle 5000# 31', 30', 30'S/O.

Agreed, do not overload. I have never even carried any type of water load with my rig.

I just hope Don.44 can get some relief for his in-route braking situation.

Towing the trailer with "FULL" water, increases the towing stability because of a lower center of gravity, especially on curves.

Full water also reduces the fuel economy, by about 2 ounces per tank full. Certainly not something to be concerned about.

Andy

[CanoeStream]

Ditto Andy's comments about carrying water. I do it on a fairly regular basis if I will be arriving late or at an unimproved campground. And especially if I know the destination has lousy water. Carrying some water is reassuring on curvy roads. And I look for all the stability I can get on strong windy days.

[GCinSC2]

Andy,
Canoestream,

I can at least try the water load. Just haven't done it yet.

Don.44

IF there is any proposal to remove the actuator and leave the brake line (that connects to the actuator) off, you can plug the line to prevent leaking and the DOT 3 from being additionally exposed to atmosphere by using a 3/8" brake line coupling and capping it with a 3/8" brake line plug.

Did you get a chance to do a visual inspection of the brake pads and rotors, anything unusual?

Gary