Clutch line anti-leak washers

carl

carl

True Classic
I poured fluid into the brake and clutch reservoirs today and of course got a leak on the clutch line where it threads into the MC. Not even a drip but the fitting gets wet. I don't remember if it was here or on MIRA but there was a mention of cup shaped washers that can be inserted between the MC and the bubble flare of the line to possibly solve this leak.

Can anyone fill me in on these and what size I need and where to get them? I want to try this before using compression fittings to install a new partial line with new bubble flare.
 
I have heard them referred to as "borsheim seals" (that spelling might be wrong). At least the ones shaped for "AN" type fittings. They are very thin and soft aluminum or copper.
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Here is one listing, look to see if they also have them for the flare fitting used on brake lines:
https://secoseals.com/seco7/

I also saw a tool that might work, but I would not spend the money for such limited use:
https://koultools.com/fix-leaky-brake-line-fittings/
Maybe something in that listing will spur ideas for solutions.
 
I have used copper crush washers and just let them seat by tightening up the connection. The trouble with the bubble flare is that repeated opening and closing of the fitting caused the bubble to compress and it just won't seal any more. By putting a copper crush washer in the fitting, it takes up some of the slop and allows the joint to be sealed. The tool above talks about 37 degree double flares, not bubble flares. I don't think it will work in this application. The bubble flare should be torqued and not reefed down as it damages the bubble whereas the 37 degree double flare can be tightened down without issue.

TonyK.

Grimsby Ontario Canada.
 
Very true about that tool and bubble flares, it won't work here. It was just something I happened on while looking for the seals.
And I also agree about reusing bubble-flared tube more than a few times...The "bubble" gets crushed and loses its seal. Ultimately the best solution is to trim off the end of the line and make a new flare if there is room to do that, or replace the line if not. But that is a pain to do, so maybe the seal will work.
I've used the seal on a 'AN' type fitting and it worked. However I don't know if they make them for a bubble flare. Seems the ones for AN or HVAC applications might not be correct here?
 
The size may be the issue. Brake lines on our cars are 3/16" and AC lines on the high side is normally 1/4" that is why a small crush washer works it is flat and just shapes to what is left in the void of the joint/fitting.

TonyK.

Grimsby Ontario Canada.
 
On my previous X I had to cut the line near the brake MC, where there is a straight run of the clutch line and make a new section out of copper alloy and then use a compression fitting to attach to the clutch line. Worked fine but was hoping to avoid that. Not really enough room for me to reflare the end of the stock tubing.

Tony, are you saying just a small flat copper washer might work? Where would I get something that small, from my local hardware store?
 
TonyK said:
a small crush washer works
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Tony, I'm with Carl here...not clear how you mean this. Do you put a standard copper crush washer in between the end of the tube (bubble flare) and the inside of the hole on the master? A crush washer seems way too thick to do that, but I can't see where else you would put it.

If you are going with the seal option rather than make a new flare, then Pauls' suggestion seems the best way. That is the type of seal discussed earlier.
 
A small washer like disk of thin annealed copper will suffice. This doesn’t need to be anything special.

The Grainger parts will work fine and are likely what you would get from a local AC company...

You can anneal copper by heating it cherry red using a low flame played across the area you want to anneal and quenching it in cold water.

(This is a correction, Tony pointed this out in the next post, this is to ensure the correct info is in both places. My apologies.)
 
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Dr.Jeff said:
Tony, I'm with Carl here...not clear how you mean this. Do you put a standard copper crush washer in between the end of the tube (bubble flare) and the inside of the hole on the master? A crush washer seems way too thick to do that, but I can't see where else you would put it.

If you are going with the seal option rather than make a new flare, then Pauls' suggestion seems the best way. That is the type of seal discussed earlier.
Click to expand...


Yes just a flat copper washer I have a set of several sizes and used one of those. I installed in the brake line at the rear as there was not enough tube to cut and re-flair with.

As for annealing copper, I though it was the opposite of steel, heat cherry red and quench. Air cooling causes it to harden.

TonyK.
 
Shoot, you are correct. Thank you Tony for correcting that.

I will mend my post. My apologies, brain fade...
 
First attempt: The 3/16" washers are too small, probably appropriate for brake size fittings but the hole diameter is smaller than the line inner diameter so I'll order the next size up which has a 3/8" outside diameter and a 3/16" inner diameter which pretty much matches the inner diameter of the clutch line. These are the 1/4" tube size flare.
 
carl said:
First attempt: The 3/16" washers are too small, probably appropriate for brake size fittings but the hole diameter is smaller than the line inner diameter so I'll order the next size up which has a 3/8" outside diameter and a 3/16" inner diameter which pretty much matches the inner diameter of the clutch line. These are the 1/4" tube size flare.
Click to expand...

Yeah the clutch line is fatter than the brake lines.
 
The copper cone shaped washers from Grainger seems to be working just fine. This was a situation on the clutch MC that the clutch line bubble flare would no longer seal properly to the MC. The crush washer solved the problem with no leak (so far). I had to get a box of 10 so if anyone wants one for the clutch or a brake bubble flare ( I bought a box of those first but they are too small for the clutch line) let me know.
 
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