Cobra4B

A few weeks back I installed fresh oem calipers that had been powdered black. The powdercoat was put all over and didn't allow the line/caliper fitting to properly seal. I caught the RF caliper leaking badly and as it turns out all of them were seeping slightly.

I posted about it here: http://forums.corvetteforum.com/show....php?t=1720527

I took the brakes off, used brake clean and q-tips to remove the powdercoat from the areas it wasn't supposed to be, and re-intalled the AN fittings w/ brand new copper crush washers.

This was the Saturday before last... I had been monitoring the fluid level and saw no change at all.

Tonight I installed my track pads and whees/tires. In doing so I noticed the LF caliper is ever so slightly seeping. What I mean is that you can see a faint bit of blue between the copper crush washer and the caliper (running ATE superblue). I was able to torque it a hair more before the fitting wanted to start to round.

The RF was dry and I had the rear on the ground before getting to look at those.

What gives? I never had an issue the first go around a few years back installing the lines.

The lines originally came w/ the flat grey colored crush washers, I went to Advanced Autoparts to get new ones and left with copper crush washers in the same size to replace... same as oem.

Here's the question... do they two different kinds work the same? The grey ones are flat on both sides whereas the copper ones are slightly rounded on one side and flat on the other.

My buddy who's a helocopter mechanic told me to put the slightly rounded side toward the caliper... does this even matter?

Any ideas? I'm going to drive it a bit to bed the pads in and then put it up in the air and pull the wheels and see what's going on.

I'm running VIR this weekend and have to trust my car 100%

Thanks,
Brian

Axelrod

I dunno. But, for street driving, if you have that little bit of seepage, absolutely do not put the car to speed till the issue is fully resolved and dry! You probably already knew this

Cobra4B

^ Yes I know this... anyone know what coule be up? Could the type of crush wahser be the issue?

I don't get it... the replacements are oem style coper ones whereas the Goodrige kit originally came w/ the grey type.

Randy? David? Anyone have input?

Oyishdog

I hope you get this fixed! Maybe you just did not tighten enough. I am a firm believer of somewhat "overtightening"

Cobra4B

^ Ryan they're installed as tight as you can w/ a 13mm socket and 1/4" rachet.

Then last night I got it to move a hair w/ a 13mm wrench, but the fitting wanted to start rounding.

I'm so confused.

Is there any benefit/difference between an aluminum crush wahser and a copper one? They lines come w/ aluminum, but of course I had to replace and used copper.

Cobra4B

Guys is there any diference in using a copper crush washer vs. aluminum?

I have 2 aluminum ones that came w/ my new rear brake lines from DRM, but needing all four I just went w/ the copper ones from Advanced for consistency.

UstaB-GS549

OEM calipers and their banjo fittings usually have concentric rings machined into their faces. This allows the soft copper washer to deform into small grooves and form multiple seals.

Is powdercoating filling in grooves in caliper? A flat surface is a little harder to seal.

c4cruiser

Was there a difference in the outside diameter between the aluminum washers and the copper ones? Is all of the powdercoat removed from where the copper washer touches the caliper? Are there any scratches on the surface of the boss on the caliper side where the washer sits?

If the copper washer is sitting on any amount of powdercoat material it may have enough of a bend in it to allow seepage under pressure (applying the brakes).

When you installed the copper washers, how did you palce them? Flat side to the caliper and rounded side to the line?

I have always used copper washers for attaching the flex lines. WhenI got my Earl's lines, they came with aluminum and I tossed them.

Cobra4B

^ I removed all the PC from the area where the copper crushes because of this. That is what I believe was causing my issue the first tim around.

I guess it's possible that I need to clean the LF one again.

Cobra4B

No same exact size except the aluminum ones are flat on both sides, yes I removed the PC as best I could... maybe I missed a little spot... no scratches I could see.
I may need to re-check the LF.
No... I did flat side out and rounded side toward the caliper. I figured it would crush and flatten out... was this wrong? I figured it didn't matter seeing as the aluminum ones are both flat. Then I called my buddy who works on heliopters and he said flat side toward the bolt head.
Gotcha.... thanks for the info.

Cobra4B

So what's the consensun on crush washer orientation? Flat side toward the caliper or toward the AN adapter?

I put the flat side toward the AN adapter... might flip it this time.

ajg1915

Flat side torwards the caliper.

Go buy yourself some teflon seal that comes in a tube. Take out lines and clean them and put on teflon in the threads of brake line and retorque. Wait about an hour and bleed brakes.

The teflon sealer will close the gaps between the threads which is probably where you are leaking.

Permatex Thread Sealant w/Teflon item 80631 (14A)

I used when I installed both sets of my Wilwoods, no leaks.

Cobra4B

^ Good call... I think I have some for connecting air fittings to my compressor.

I guess I'll do that and instal a new washer in the other oreintation.

0Randy@DRM

Both of the washers should work no problems. This is a strange problem, did you try a different washer? The other thing is powder coating calipers is risking business. I would sand off all the powder coat around the sealing surface and try new washers.

Randy

Cobra4B

^ Randy I allready did that the first go around I removed all the PC and re-installed w/ new crush washers. PM sent.

Aardwolf

As far as I know you install the chamfered side of the washer toward the bolt head. I used the aluminum washers that came with the lines and no sealant, I had no problems.

It is possible to install the fitting into the caliper backward. You didn't do this did you? The lines that I got have a fitting that goes into the caliper and then the line screws onto it. This fitting is smaller on one side then the other. If you put the small side into the caliper it would leak past the threads.

Also the washer goes against the caliper.

In this application I doubt the chamfer of the washer would make any difference.

0Randy@DRM

Well after reading your PM. I don't have a clue on which side of the washer goes down. I guess we never looked into it that deep. My best guess would be the flat side down. Taping or glueing the threads is kinda a huge bandaid. The threads are straight and dont work like pipe threads at all. Will it hurt? No but it may mask a bigger issue.

Randy

Cobra4B

^ Ok...

*The theads were never powdercoated, they are clean.
*The crush washer contact surface was coated originally, but I cleaned them out after they started leaking.
*I used new crush washers but put the rounded part down.
*The AN adapters can only screw into the caliper one way, they are correct.
*The copper washers are between the adapter and the caliper.

Aardwolf

My Goodridge lines have a fitting that screws into the end of the line and on the other side, screws into the caliper. This fitting is smaller on one side. I installed this fitting large side into the caliper, then installed the line onto it. Your lines are not made this way?

The ones I have could install both ways, the threads on the small end of the fitting will engauge the caliper.

Cobra4B

^ If you install them backwards then you woulnd't be able to install the line properly. The AN fitting seals on the angled edge. The part that screws into the caliper doesn't have the same end. Plus mine are slightly different thicknesses to prevent this.