Brake Line Placement for TT Disc Brakes

If my brakes are a "little bit spongy" I certinly don't notice it. Remember, disc brakes will more than make up for a micro second on lag. And my 30 footer has the wheels in the middle and the pump is behind the overhang. The first wheel is less than 10 feet from the pump. Does somebody think they are using 30 ft of hose? I would think I used about 25//27 ft total and mine is all flex.

Excuse me, Ron W - but you have no idea of what my professional experience is with vehicle brakes. Evidently you do not have a clue as to what Kodiak admitted with their products except by what the OP posted.

If you feel the need to cast stones at people or product vendors, please make sure they go in the right direction with the correct pertinent information.

rjsurfer wrote:
I did the upgrade to disc brakes and because of issues with my flaring I went with all pre made flexible hoses and all I can say is I can't detect ANY sponginess or delay at all.

The upgrade has made driving the rig enjoyable, step on the brakes and it stops.

Remember where your coming from, 1950 drum brake tech.....

Best mod so far, and its not just the improved stopping distance it's the perfect modulation. With the drums I could never get the controller set right for all!situations. In the year I have had the discs I have adjusted the controller once!..I even have to think about how to adjust them. I forgot how.

Don't listen to the naysayers trying to scare you with stories of increased delay and that ****, they are all people who have not made the mod and they think they know what will happen without even doing the upgrade.


Ron W

The 5r in your signature (I assume less than 30 ft. in overall length??) probably required less than 20 ft. of flexible brake line for the primary run. According to Kodiak you shouldn't experience any delay or sponginess issues when less than 20 ft. of flexible brake line is used for the primary run. And, to reiterate, if you do use more than 20 ft. of flexible brake line for the primary run, you will still get maximum braking power. However, there may be a very slight delay before maximum braking is achieved.

I used to deliver mail on a rural route. I replaced the stock flexible brake lines with Stainless Steel braided lines, so as to minimize having an issue. Don't know but I would think those would provide a better solution for the flex lines? Just a thought!

Irelands child wrote:

otrfun wrote:
It just occurred to me, if one really wants to get the absolute best response time from their disc brakes, I suppose mounting the actuator somewhere near the axles themselves would certainly help. That would dramatically reduce the length of the primary brake line run. Of course, you'd want to mount it in a safe, secure location, along with using appropriate gauge wires commensurate with the longer run length.

That's absolutely correct - except in my case, our 5er doesn't have any compartment close by. Then as you said there is that need to run at least 4 individual lengths of 12awg wire to the 7 pin plug/breakaway wiring - and that's an interesting challenge too particularly if the RV's belly is covered such as ours.

For jacking - I drop the front legs as far as possible then crib up to the frame behind the axle and as close to the spring hangers as possible using mostly 4x4 by 16" long. This gives me 6 lengths per 8 foot long board. I then raise the landing gear far enough to get the wheels of the ground, add a pair of 6 ton/pair stationary jacks along with the LG. I wont jack anywhere on the axle except under the spring hanger - that 3" tubing is just too fragile. As it stands now, the two longer flex lines may be too short for mine without a standoff from the belly. We'll see in about 4 months or when the predicted snows are gone

Amazing that Kodiak admitted to potential spongy brakes. If I wanted crappy brakes - the trailer already has them and I don't need to spend 12-1400 bucks for discs

I did the upgrade to disc brakes and because of issues with my flaring I went with all pre made flexible hoses and all I can say is I can't detect ANY sponginess or delay at all.

The upgrade has made driving the rig enjoyable, step on the brakes and it stops.

Remember where your coming from, 1950 drum brake tech.....

Best mod so far, and its not just the improved stopping distance it's the perfect modulation. With the drums I could never get the controller set right for all!situations. In the year I have had the discs I have adjusted the controller once!..I even have to think about how to adjust them. I forgot how.

Don't listen to the naysayers trying to scare you with stories of increased delay and that ****, they are all people who have not made the mod and they think they know what will happen without even doing the upgrade.


Ron W

My old Imperial Eastman double flare button didn't work very well so I made my own button that produced a much wider double flare. Then after using the button to start the double flare I used a small rivet hammer to pound the double flare inward before using the flare tool the second time and that kept the double flare the same I.D. as the tubing. It takes practice so start on a sacrificial piece of tubing before you cut an exact length and botch the flare. Craig

Irelands child wrote:
. . . For jacking - I drop the front legs as far as possible then crib up to the frame behind the axle and as close to the spring hangers as possible using mostly 4x4 by 16" long. This gives me 6 lengths per 8 foot long board. I then raise the landing gear far enough to get the wheels of the ground, add a pair of 6 ton/pair stationary jacks along with the LG. I wont jack anywhere on the axle except under the spring hanger - that 3" tubing is just too fragile. As it stands now, the two longer flex lines may be too short for mine without a standoff from the belly. We'll see in about 4 months or when the predicted snows are gone

Amazing that Kodiak admitted to potential spongy brakes. If I wanted crappy brakes - the trailer already has them and I don't need to spend 12-1400 bucks for discs

Great idea using the front landing gear to leverage the rear of the 5r. Not sure if my 5r's single landing gear motor would have the cajones to do a lift like that. Pin weight is about 2,800 lbs. and it struggles a bit with that. The landing gear has 4 zerk fittings that I've greased the hell out of. That helped, but it still struggles.

Ref Kodiak disc brakes and the use of flexible brake lines, the rep did make it clear you will get full braking force regardless of the run length; however, there may be a slight delay to allow time for the pressure to build-up if your primary run of flexible brake line is longer than 20 ft.

otrfun wrote:
It just occurred to me, if one really wants to get the absolute best response time from their disc brakes, I suppose mounting the actuator somewhere near the axles themselves would certainly help. That would dramatically reduce the length of the primary brake line run. Of course, you'd want to mount it in a safe, secure location, along with using appropriate gauge wires commensurate with the longer run length.

That's absolutely correct - except in my case, our 5er doesn't have any compartment close by. Then as you said there is that need to run at least 4 individual lengths of 12awg wire to the 7 pin plug/breakaway wiring - and that's an interesting challenge too particularly if the RV's belly is covered such as ours.

For jacking - I drop the front legs as far as possible then crib up to the frame behind the axle and as close to the spring hangers as possible using mostly 4x4 by 16" long. This gives me 6 lengths per 8 foot long board. I then raise the landing gear far enough to get the wheels of the ground, add a pair of 6 ton/pair stationary jacks along with the LG. I wont jack anywhere on the axle except under the spring hanger - that 3" tubing is just too fragile. As it stands now, the two longer flex lines may be too short for mine without a standoff from the belly. We'll see in about 4 months or when the predicted snows are gone

Amazing that Kodiak admitted to potential spongy brakes. If I wanted crappy brakes - the trailer already has them and I don't need to spend 12-1400 bucks for discs

It just occurred to me, if one really wants to get the absolute best response time from their disc brakes, I suppose mounting the actuator somewhere near the axles themselves would certainly help. That would dramatically reduce the length of the primary brake line run. Of course, you'd want to mount it in a safe, secure location, along with using appropriate gauge wires commensurate with the longer run length.

Irelands child, looks like you're more than ready when spring rolls around. Thanks for elaborating on your planning and preparation. It's helpful. As for us, we're hoping we don't have to wait till spring. We're in the desert SW where sunny days with reasonably warm temps are still in the foreseeable forecast.

I called Kodiak directly about their flexible line kits. I spoke to a gentleman who said he actually installs these kits in the TX area. He said if flexible lines longer than 20 ft. are used for the primary run, braking action can get a little delayed or spongy---20 ft. or less supposedly not an issue. Like you, I'm not going to take any chances. Even though my primary run is going to be around 17 ft., I still have plans to use metal. I'll also be terminating into the caliper assemblies and actuator using flexible lines. If for no other reason than to facilitate any R&R down the road.

Although I appear to be focusing on the installation itself, have to admit I'm also concerned about safely jacking up my 5r for this installation. I want to get my jack stands as close to the brake assemblies as possible to prevent any unnecessary flexing of the axle tube. To do this requires placing my bottle jacks inboard on the axle about 12-14 inches (from the brake assemblies) in order to place the jackstands. I'm hoping that's not an issue. At some point the bottle jack can be placed too far inboard on the axle, which could cause bending and flexing of the axle tube.

As always, thanks to everyone for their helpful replies!