Kodiak Disc Brake Engagement Delay--Is This Normal?

[howson]

I had Kodiak disc brakes installed on my 315RLTS by MORryde after the rally. I've now towed over 1,800 miles with the new brakes and (still) haven't gotten used to how they feel. I've complained once to MORryde and before I complain again I'm looking for confirmation there really is a problem.

The issue is the delay in engagement. When I press on the brake pedal there is about a 3 second delay before I can feel the disc brakes engage. What happens is I press too hard on the brake pedal initially (since the truck is doing all the work) and when the disc brakes kick in I have to modulate (lighten) the pedal pressure or I stop too quickly. Maddening.

Is this delay normal?

The video below will demonstrate the issue and shows my settings. Below the video are two pictures showing (I used my video editing program) when I said "mark" each time, so I know there is a 3 second delay.

[colan]

A few thoughts:

Bleed the brakes, pump a lot of fluid through to ensure no air in the system.

One of the downsides I see to electric over hydraulic brakes is the delay as the pump builds up pressure. If I recall correctly the time to come up to pressure is around 1/2 second. Your delay seems excessive.

I generally will set the gain to the point I KNOW the trailer brakes are working which results in over braking a few seconds after applying the brakes. My foot has learned to compensate and ease up as I feel the trailer start to over brake.

[JCR GD]

Is there a setting in the truck controller for "electric over hydraulic"? It seems like I have seen it or heard of it. Will it make a difference?

[Cate&Rob]

When I press on the brake pedal there is about a 3 second delay before I can feel the disc brakes engage.

Hi Howard,

3 seconds is definitely not right. As Colan notes, engagement should be about 1/2 to 1 second after brake apply and the most likely cause is air in the hydraulic lines. The actuator has to compress all the air before there is enough hydraulic pressure to apply the trailer brakes.

The hydraulic pipes and hoses should be as horizontal as possible to prevent high loops where the air bubbles will gather and will be difficult to purge out. I had to re-route some of the hoses in my installation to finally get all the air out on the 3rd purge process. See page 26 of the attached for the brake bleeding process.

It is also important to have your truck set to "electric over hydraulic" rather "electric" trailer brakes.

Rob

[gbkims]

Hi Howard,

Is this is happening at all speeds?
If you use Manual Brake Lever can you tell when the actuator pump starts?
Bleeding again would seem a good idea.

What brand & model of actuator is installed?
I'd read they actuate in .3 sec for Titan Brakerite and about 1 sec for Dexter DX, Carlisle/Hydrastar.
Actuator Time https://www.expediter.com/wp-content...star-Flier.pdf

The smart integrated brake controllers reduce voltage to the actuator depending on speed.
2017 F350 - Towing
The trailer brake controller is equipped with a feature that reduces output at vehicle speeds below 11 mph (18 km/h) so trailer and vehicle braking is not jerky
or harsh. This feature is only active when applying the brakes using your vehicle's brake pedal, not the controller.


Titan Brakerite EHB Actuator
Poor response time Check and add brake fluid as required (figure 5.4.2A-pg.22)
Bleed brake lines and devices
Check input for adequate “charge” (12 VDC)

Dexter DX Series http://stopyourtrailer.com/wp-conten...lit-608-00.pdf
Re-bleed the trailer brakes. Any air in the trailer brake system causes brake delay.
Trailer wiring that is too small can cause slow response (see section on Electrical Installation Requirements).
Check to see if the white ground wire runs directly to the tow vehicle ground. IT MUST NOT BE GROUNDED TO THE TRAILER ONLY.
IT IS IMPORTANT THAT THIS GROUND WIRE RUNS DIRECTLY TO THE TOW VEHICLE'S BATTERY GROUND. NO EXCEPTIONS.
6. Some brake controllers will not produce a high enough signal voltage to actuate the trailer brakes when the vehicle is at a standstill. Minimal traler brake force is produced when the controller voltage output to the E/H brake actuator is at least 3 VDC. Maximum trailer brake force is achieved at 12 VDC on the actuator blue wire.


Carlisle Hydrastar
As a precautionary measure, CARLISLE ® recommends bleeding the brakes a second time after the trailer has been in service for 7 – 10 days.

Brakes are slow to respond
• Re-bleed the trailer brakes and actuator.
• Slow response can be caused by trailer wiring that is too small. See Section C. ELECTRICALINSTALLATION REQUIREMENTS – WIRE SIZE IS CRITICAL / LOW VOLTAGE CONDITION.
• Slow response can be caused by brake lines that are too restrictive on the trailer (i.e. small diameter / long length restrictive fittings / routings).
• The trailer brake lines must be at least 3/16 inches in diameter / steel tubing is preferred over flexible hoses.
• If it is not practical to locate the HydraStar™ unit closer to the brakes, consider increasing the size of the trailer brake lines

[Cate&Rob]

I'd read they actuate in .3 sec for Titan Brakerite

howson
My Titan Brakerite actuator comes on as soon as I hit the brake pedal . . . probably the .3 sec that Gene quotes. I can hear the actuator in the front compartment of the trailer, from the driver's seat with the window open and moving at a moderate speed. There is still a short time (maybe another half second) as the actuator spools up and applies hydraulic pressure to the calipers. A little "un-nerving" if you are used to the faster apply of electric drum brakes, but something that is easy to get used to. The EoH trailer disc brakes are very easy to modulate. My OEM dash display shows a bar graph between 0 and gain setting. On most normal braking, trailer apply is about half the gain setting. This matches truck and trailer quite evenly. If I need to brake hard, the graph goes immediately to full gain (I use a setting of 7) and I can feel the trailer pulling back on the truck. On wet roads, I back gain off to 5. The truck has ABS . . . the trailer does not. The last thing you want in heavy braking on a wet road is a sliding trailer!

Rob

[howson]

Is there a setting in the truck controller for "electric over hydraulic"? It seems like I have seen it or heard of it. Will it make a difference?

As shown in the video, I do have it set to "Electric over Hydraulic". Does it make a difference versus the standard setting? I don't know...I set it as shown per MORryde's direction.

[howson]

Hi Howard,

3 seconds is definitely not right. As Colan notes, engagement should be about 1/2 to 1 second after brake apply and the most likely cause is air in the hydraulic lines. The actuator has to compress all the air before there is enough hydraulic pressure to apply the trailer brakes.

The hydraulic pipes and hoses should be as horizontal as possible to prevent high loops where the air bubbles will gather and will be difficult to purge out. I had to re-route some of the hoses in my installation to finally get all the air out on the 3rd purge process. See page 26 of the attached for the brake bleeding process.

It is also important to have your truck set to "electric over hydraulic" rather "electric" trailer brakes.

Rob

Thanks, Rob. Based on what you've written and colan 's input I'm going to have to bleed the system--when I get home. I am not going to attempt anything while on the road outside of emergency repairs or experimenting with settings.

[Cate&Rob]

As shown in the video, I do have it set to "Electric over Hydraulic". Does it make a difference versus the standard setting? I don't know...I set it as shown per MORryde's direction.

Hi Howard,

Guest
I set mine to "Electric over Hydraulic" (as directed) and it works. I would also be interested to know what the difference is?
Jim ??

Rob

[howson]

Hi Howard

Is this is happening at all speeds? YES
If you use Manual Brake Lever can you tell when the actuator pump starts? YES--it is quite loud
Bleeding again would seem a good idea. Yep--will attempt when I get home. I wonder if anyone's tried SpeedBleeders? They work great on my Goldwing.

What brand & model of actuator is installed? Brand is Hydrastar. Model? Not sure--it's either a HBA-10, HBA-12, HBA-16, MHBA-10, MHBA-12 or MHBA-16 I'll have to crawl underneath again tomorrow night and see if I can see a model number.

https://www.hydrastarusa.com/pdfs/In...20Manual_2.pdf



I'd read they actuate in .3 sec for Titan Brakerite and about 1 sec for Dexter DX, Carlisle/Hydrastar.
Actuator Time https://www.expediter.com/wp-content...star-Flier.pdf

The smart integrated brake controllers reduce voltage to the actuator depending on speed.
2017 F350 - Towing
The trailer brake controller is equipped with a feature that reduces output at vehicle speeds below 11 mph (18 km/h) so trailer and vehicle braking is not jerky
or harsh. This feature is only active when applying the brakes using your vehicle's brake pedal, not the controller. During the test I was using the controller, so the full gain (8) was applied.

[howson]

howson
My Titan Brakerite actuator comes on as soon as I hit the brake pedal . . . probably the .3 sec that Gene quotes. I can hear the actuator in the front compartment of the trailer, from the driver's seat with the window open and moving at a moderate speed. There is still a short time (maybe another half second) as the actuator spools up and applies hydraulic pressure to the calipers. A little "un-nerving" if you are used to the faster apply of electric drum brakes, but something that is easy to get used to. The EoH trailer disc brakes are very easy to modulate. My OEM dash display shows a bar graph between 0 and gain setting. On most normal braking, trailer apply is about half the gain setting. This matches truck and trailer quite evenly. If I need to brake hard, the graph goes immediately to full gain (I use a setting of 7) and I can feel the trailer pulling back on the truck. On wet roads, I back gain off to 5. The truck has ABS . . . the trailer does not. The last thing you want in heavy braking on a wet road is a sliding trailer!

Rob

I need to test to see how long it takes from brake actuation to hearing the pump. Somethings not right, and I must admit I'm a little annoyed.

[Guest]

Hi Howard,

Guest
I set mine to "Electric over Hydraulic" (as directed) and it works. I would also be interested to know what the difference is?
Jim ??

Rob

Rob,

I've not looked into this to give you an exact answer but the electrical load on four standard trailer brake electromagnets would certainly be different than a simple signal to the Kodiak brake controller. The electric over hydraulic system would only need a low current, direct or scaled voltage to the brake circuit of the truck. I would try to bleed the trailer brakes first before assuming the Kodiak system is defective. What gain are you using Rob?

Howard bleeding the Kodiak brake system would be easy to do. Just make sure you use the correct brake fluid.

Jim

[Cate&Rob]

Rob,

I've not looked into this to give you an exact answer but the electrical load on four standard trailer brake electromagnets would certainly be different than a simple signal to the Kodiac brake controller which would only need a low current, direct or scaled voltage to the brake circuit of the truck. A gain of 8 that Howard is using seems suspicious where I would try to bleed the trailer brakes first before assuming the Kodiac system is defective. What gain are you using Rob?

Jim

Hi Jim,

Agreed that the the truck feed to electric drum brakes is going to be about 12 amps (4 x 3 amps per magnet) The EoH actuator is only looking for a voltage signal. I run a gain of 7 which means that the trailer braking is greater than truck braking on heavy apply, but not enough to lock up the trailer brakes on dry pavement. On normal braking, apply is about half of gain setting and closely matches trailer and truck braking. See my earlier post on this thread.

Rob

[Guest]

Rob,

Well I guess it helps to be in controls for a living. I edited my post where I see Howard is using a gain of 7 so this does not seem to be out of line.

For Howard.....bleeding the Kodiak system should be easy but I'll take another shot and state to bleed in short bursts to check fluid and allow the pump motor to cool. As long as the bleeder is open and the brake activated, the pump will continue to pump until its dry. Wear eye protection since brake fluid in the eyes will burn like fire. Since the pump on your Kodiak system is low volume/high pressure, its plausible a delay would be encountered if air is present in the system.

Jim

[howson]

I found the model # of the Hydrastar controller tonight on the box--it's an HBA-16. There's a good video by etrailer on the installation at https://images.etrailer.com/static/i...tor-hba16.webm

The bleed process starts at about the 14:18 mark of the 17+ minute video. (I don't recommend spraying the brake fluid on the ground like the tech does in the video! Sheesh.)

Before I actually bleed the brakes I'll try to determine a definitive, repeatable engagement timeline. After the bleed I'll compare against the starting point to see if it made any difference.

Finally, and also according to etrailer, the controller in my '17 F-350 is compatible with the Hydrastar, so that concern is put to rest. (There's warning labels all over the unit about requiring a compatible controller.)

The weather may be rotten here on the Emerald Coast tomorrow, so I'll post the results once I'm able to actually do the brake bleed.

-Howard