Problems with Roll Control install...

[J Banning]

I've just finished putting a Hurst Roll Control in my car ($109 from Summit), and will start on another one tomorrow for a friend. I had some problems with mine and need some input...

The problem...
When looking at the body of the Roll Control, you have the threaded holes that your brake line goes into. Well, the threads for both the input and output lines (yes, the were double flared) were not tapped all the way to the bottom of the hole. The threads look to stop about 1/16 - 1/8" short. The nut on the brake line would not seat correctly because of this. It would hit the end of the threads in the hole in the Roll Control, and would not press the flared line into the body of the unit. Fluid would leak out of the fitting between the line and the nut.

WTF?

The fix...
I rigged mine by using a bench grinder and flat file to remove the first 3 rows of threads on the brake line nut. It does not appear to leak now, but it's a B.S. way to do the job. I REALLY don't want to do this on the other unit.

[Why did this happen?[/b]
BOTH of these units (both ordered from Summit at the same time) are line this. The only thing I can think of is that they may have been made incorrectly.

Any thoughts?

Thanks,
-Banning.

 

[turbojimmy]

My Biondo was the same way. I had ordered the $15 "installation kit" from Summit as well. I put brass fittings (like adapters) in each end of the line lock, and the brake lines tapped into those. Pic here:

http://www.turbojimmy.com/line_lock.jpg

Jim

 

[John Larkin]

I installed the ACD unit (looks just like the Biondo of Jimmy's). I used NPT fittings with Teflon sealant to adapt the brake lines. My solenoid didn't even appear to have a double flare recepticle inside, just fluid passages, somewhat offset at that; I'm surprised the Hurst did. Needless to say, no problems other than alot of trial fitting and line bending since I mounted mine under the car post-proportioning valve (as per NHRA rules with a momentary switch).

 

[UNGN]

Ummmm...you are supposed to use npt to inverted flair adapters in the body of the line lock, then thread the lines into the adapters. I found the same thing when I wrote up an install procedure last summer. Nothing in the Hurst procedures say this is required but if you don't, brake system failure could occur.

The proper adapters are contained in the Hurst install kit.

 

[tom h]

J Banning ,

You may be very reluctant to do so now, but I would be inclined to disassemble those brake lines that were accidentally threaded into the Hurst's taperd NPT threads, and inspect the brake line flares carefully for any damage.

I believe the Hurst body is stainless (hard material), the brake lines are hard, and there is some risk here of galling or nicking.

The nature of flares is such, that any MINOR imperfections should "coin" out or seal OK. Most flare adapters (Flare tube to male NPT thread) are brass, softer than the steel brake tubing, so MINOR imperfections result in the brass conforming to the steel flare.

Since the Hurst's tapered NPT seals on the threads, not at a "face seal" at the bottom of the ports, any slight damage at the port bottoms should not affect integrity.

But, if everything has been already reassembled, and bled, and there are **NO** leaks, you're a lucky guy and are probably OK to leave it alone.

Just so everyone's on the same page,
- Tapered NPT threads require some kind of thread sealant (I like the soft, non-hardening Permatex).

- Flares (Inverted or 37º JIC or 45º SAE) must **never** use any thread sealant, either on the threads or the face seal . The seal is where the flare compresses against it's mating surface. If it leaks after torquing to Mfr's recommendation, replacement is indicated. It is VERY rare for these to be manufactured wrong.

 

[Chuck Leeper]

Lines direct to LL???

ABSOLUTELY DO NOT use the car til the lines are replaced, the inverted flare adapters added and the threads in the LL body are verified. There is NO way for the inverted flare on the brake line to seat w/out the adapters. [You can get the adapters from most auto parts stores.]
AT A MINIMUM, the line fittings must be replaced.. Unless you have a double flare tool, DO NOT attempt to do this. Buy new lines. DO NOT use a single flare. The inside of common brake line, [AKA Bundyflex], has a seam where it's welded. A single flare exposes this seam to the sealing surface in the flare adapter and WILL cause a leak, or worse, it will crack at the seam, rendering the line JUNK!!
Additionally, BE SURE the lines are connected to the proper ports on the LL. Incorrect ports will make the LL inoperative.

 

[tom h]

I just realized that the way I wrote my post above, might be interpreted as "OK to leave flare lines screwed into NPT ports"

ABSOLUTELY NOT, as Chuck says.

What I meant was, IF the brakelines were removed from the Hurst NPT ports and had been correctly screwed into the CORRECT inverted flare adapters and leaktight, then perhaps ANOTHER disassembly for the sole purpose of inspecting, ought not to be required.

But really, I think Chuck's recommendation (take it all apart again, a 2nd time), is the "right" way...

Definitely don't leave any inverted flare tubes screwed into anything but the correct Inv Flare adapter...

 

[UNGN]

I'll bet money there are hundreds if not thousands of people who did what J Banning did. Of the 6 to 8 pages of instructions hurst provides with their line lock, no where is there a warning to use the inverted flair adapters. Don't anyone tell your lawyers about this one, it's a lawsuit waiting to happen.

 

[tom h]

on my set of hurst instructions, hurst *does* state to install fittings into the valve body ports, but it's not prominently labelled with conspicuous warnings. It's just a few ordinary lines of instructions, but it's there if you read the instructions carefully.

With the various problems reported, I agree it would be better if they had a CLEAR graphic or drawing, with a few prominent Cautions or Warnings.

 

[AsphaltAnihil8r]

Originally posted by UNGN
I'll bet money there are hundreds if not thousands of people who did what J Banning did. Of the 6 to 8 pages of instructions hurst provides with their line lock, no where is there a warning to use the inverted flair adapters. Don't anyone tell your lawyers about this one, it's a lawsuit waiting to happen.

Maybe I should go and buy a Hurst LL

 

[Chuck Leeper]

HURST AND CO.

As far as quality of the product goes.. The HURST LL is by far the best.
I have tried several others and found that the threads are not true NPT and that the fittings will screw all the way in and not seal, the bodies are nasty looking, etc. [Taiwaneese JUNK!!]
I guess that's why they sell for less.. You get what you pay for. No free lunch at my shop when it comes to items and workmanship that hangs my butt out to dry.....
I agree on the sealer. I use Permatex teflon...PIPE THREADS ONLY!!!

Everytime I see/hear of a brake failure, I think of the cowboy on his horse as they go over the cliff... WHOA, you SOB!!

 

[strikeeagle]

1. Hurst Roll/Control
2. Hurst Roll/Control Installation Kit
3. "... qualified and certified auto mechanic" (as expressly stated in the instructions)

 

[J Banning]

Thanks for the info guys. From your replies I've found the problem, and I feel like a complete dumbass for missing this... I was missing the adapters from the brake lines to the body of the solenoid.

Thanks,
-Banning.

 

[rastaz]

Originally posted by UNGN
found the same thing when I wrote up an install procedure last summer.

UNGN, are the install procedures that you wrote up posted anywhere on the net?. If not can you e-mail them to me?

Thanks

 

[strikeeagle]

http://www.mrgasket.com/hurstmain.html

From the pull down menu at the top of the page:

Instruction Sheets
Click on Hurst
Click on Accessories / Roll/Control