Technical Crush Washer on brake lines to caliper

[Rlbow43]

I have a 1980 spider 2000. I've been working on the brakes. Needed to replace all calipers. I'm having trouble stopping brake fluid from leaking from the brake line where it connects to the caliper. So far I've only been working with the leak at driver's side front brake - it's closest to the master cylinder. When I put more fluid in the master the driver's side front brake line leaks where it is attached to the caliper. I've replaced the crush washers, but the leak persists.

Is there a secret to tightening the bolt - say a torque number I should be aware of? I just cannot seem to stop the leak. This simple brake job seems to have a life of it's own. Find an answer to something and 2 more things seem to appear. This should have been done long age. UGH!

Any suggestions are appreciated. Thanks.

 

[bugsymike]

I have a 1980 spider 2000. I've been working on the brakes. Needed to replace all calipers. I'm having trouble stopping brake fluid from leaking from the brake line where it connects to the caliper. So far I've only been working with the leak at driver's side front brake - it's closest to the master cylinder. When I put more fluid in the master the driver's side front brake line leaks where it is attached to the caliper. I've replaced the crush washers, but the leak persists.

Is there a secret to tightening the bolt - say a torque number I should be aware of? I just cannot seem to stop the leak. This simple brake job seems to have a life of it's own. Find an answer to something and 2 more things seem to appear. This should have been done long age. UGH!

Any suggestions are appreciated. Thanks.

After many years in the trade and now retired at 70, I have never torqued a brake pipe fitting in my life, it is just feel and experience that it is tight enough.
So in general terms, if the surfaces are clean and there are is no minute crack in the caliper at that point (highly unlikely on more than one) then you are down to poor quality hard copper washers (they can vary) or possibly, try a "little tighter" in case just not tight enough, not excessive.
Never use anything other than the correct copper washers due to the pressure it needs to stand.
After fitting any brake part, I always got an assistant to hold the brake pedal firmly down like an emergency stop for 30 seconds or so whilst I checked for leaks.
In the old days people used to remove a solid copper head gasket, warm it up and quench it in a process known as annealing which made the copper soft again so it could be a better seal to be reused.
I am not suggesting that, merely showing copper has various characteristics that poor quality copper washers may not have, affecting their sealing capabilities assuming they are tight enough etc.
One other point some later makes of car used a design of brake hose that had a flare (no copper washer) not unlike that on a metal brake pipe which matched a corresponding design shape in the caliper/brake cylinder etc. though unlikely on yours I would have thought, especially if new brake hoses were correctly supplied and copper washers etc.

 

[s130]

Copper washer can be tricky. On our Tempra (when we had it) the fuel filter Banjo connections always leaked. There is a solution you can try that has always worked for me.

Anneal the copper washers first. Heat then in a blow torch till them just glow red with heat and then let them cool naturally - DO NOT QUENCH. Once cooled down the washer will be a lot softer and will readily form and seal with just no effort/force required.

 

[bugsymike]

Copper washer can be tricky. On our Tempra (when we had it) the fuel filter Banjo connections always leaked. There is a solution you can try that has always worked for me.

Anneal the copper washers first. Heat then in a blow torch till them just glow red with heat and then let them cool naturally - DO NOT QUENCH. Once cooled down the washer will be a lot softer and will readily form and seal with just no effort/force required.

This is the way we used to do it:-
How to anneal copper at home?


To anneal copper you need to raise its temperature to around 450c, and then plunge it into cold water. If you don't have a suitable torch you can use an oven if it will reach a sufficiently high temperature. or use the flame on a gas stove.6 Oct 2021.
So different opinions.???

 

[vexorg]

Are the sealing surfaces on the caliper and bolt good?
Can you see exactly where it's leaking from? Caliper face or bolt face? Or somewhere else?

 

[s130]

This is the way we used to do it:-
How to anneal copper at home?


To anneal copper you need to raise its temperature to around 450c, and then plunge it into cold water. If you don't have a suitable torch you can use an oven if it will reach a sufficiently high temperature. or use the flame on a gas stove.6 Oct 2021.
So different opinions.???

I've never quench (plunge into cold water) as this tends to harden materials as I recall. Maybe with copper the quenching does not cause that much hardening?

 

[bugsymike]

I've never quench (plunge into cold water) as this tends to harden materials as I recall. Maybe with copper the quenching does not cause that much hardening?

I think it depends on the metal, on mild steel I made a tool then heated it to cherry red and quenched in old oil to give it some toughness, I don't make any claims on metallurgy but that tool lasted many years undoing 2CV rear hubs.

 

[jackwhoo]

Copper annealing is heat to cherry red and drop into cold water......or the cold tea I always have due to not stopping long enough to drink it hot.....Do not drink the water or tea copper dropped into.

 

[jackwhoo]

I suggest to op new washers , very gentle tighten-if you must use torque wrench 15lb feet. Hard press on pedal and hold for a bit , then check for leaking. If leaking tighten a further "smidge" clean, press pedal , check again

 

[Rlbow43]

Are the sealing surfaces on the caliper and bolt good?
Can you see exactly where it's leaking from? Caliper face or bolt face? Or somewhere else?

The calipers (all 4) are new, so I don't think the surface would be a problem, but I will take a look once I can anneal the washers. I am reusing the original bolt. It screws in and gets very tight, but I will look at it also. In the end, whatever works on the drivers front brake I will do the same for the other 3 wheels.

No, I cannot see where the leak is. The outside of the caliper (below the brake hose) is wet when it leaks so I'm assuming it is coming from the connection of the brake hose and the caliper. And, the leak lessens when I tighten the bolt - must be coming from that connection?

I do think I've over tightened the bolt, so I hope annealing the washers will do the trick.

Thanks for the help.

 

[Rlbow43]

I suggest to op new washers , very gentle tighten-if you must use torque wrench 15lb feet. Hard press on pedal and hold for a bit , then check for leaking. If leaking tighten a further "smidge" clean, press pedal , check again

I did get new washers from a local auto parts store (NAPA). No one caries parts for a 1980 Fiat where I live - Eugene, Oregon. USA. People just look at me and shake their heads when I tell them what I'm working on.

I don't have to press on the pedal to see if it's leaking. When the master cylinder has enough fluid it will leak at this particular wheel since it is almost under the master cylinder. I expect to have the same problem at all the rest of the wheels. Ugh!

 

[Rlbow43]

Thanks for the many replies. I tried annealing 2 washers using a propane torch (that's all that I have). Could not get the washers hot enough. Put the washers on a cement paver stone. I wonder if the paver acted like a heat sink and just drew the heat off the washers. What surface should I use to put the washers on for annealing? I used the torch outside and I could not see the point of the flame so that could also be a problem. Will try just inside the garage where I might be able to see better and keep the hottest part of the flame on the washers.

I'll keep trying and post results. Thanks again for all the help.

 

[Rlbow43]

Thanks for the many replies. I tried annealing 2 washers using a propane torch (that's all that I have). Could not get the washers hot enough. Put the washers on a cement paver stone. I wonder if the paver acted like a heat sink and just drew the heat off the washers. What surface should I use to put the washers on for annealing? I used the torch outside and I could not see the point of the flame so that could also be a problem. Will try just inside the garage where I might be able to see better and keep the hottest part of the flame on the washers.

I'll keep trying and post results. Thanks again for all the help.

This the OP: I looked up annealing copper. You can let it cool by itself, but using cold water is supposed to work better - the copper will be softer if you plunge the copper into water.

 

[bugsymike]

The calipers (all 4) are new, so I don't think the surface would be a problem, but I will take a look once I can anneal the washers. I am reusing the original bolt. It screws in and gets very tight, but I will look at it also. In the end, whatever works on the drivers front brake I will do the same for the other 3 wheels.

No, I cannot see where the leak is. The outside of the caliper (below the brake hose) is wet when it leaks so I'm assuming it is coming from the connection of the brake hose and the caliper. And, the leak lessens when I tighten the bolt - must be coming from that connection?

I do think I've over tightened the bolt, so I hope annealing the washers will do the trick.

Thanks for the help.

Is this the type of hose like a banjo fitting with copper washers either side of the banjo, if so I understand your concerns when tightening? That type of drilled bolt is inherently weaker and I have also noted that if reusing the hose , maybe due to changing a caliper for instance then unless fitting new washers it is critical that the original washers are not flipped etc. but go back in exactly their original position to seat securely.
Whilst annealing may help, good quality new copper washers should have not needed it as they should be soft enough from new , as never "work hardened".
Propane torch should be hot enough and if you just thread them on an old screwdriver or bit of wire you should get them hot, not too hot as they may distort.

 

[s130]

Thanks for the many replies. I tried annealing 2 washers using a propane torch (that's all that I have). Could not get the washers hot enough. Put the washers on a cement paver stone. I wonder if the paver acted like a heat sink and just drew the heat off the washers. What surface should I use to put the washers on for annealing? I used the torch outside and I could not see the point of the flame so that could also be a problem. Will try just inside the garage where I might be able to see better and keep the hottest part of the flame on the washers.

I'll keep trying and post results. Thanks again for all the help.

Hold the washers in a needle point pliers or hang them on a length of steel/copper/galvanized wire. You need *minimal* conduction to other surfaces. I hang them on a wire and getting them to glow is not a problem.

 

[vexorg]

Tbh, I've never had any issues with just new copper washers fitted.

Clean it up, get someone to push the brake pedal see where it comes from.

 

[bugsymike]

Tbh, I've never had any issues with just new copper washers fitted.

Clean it up, get someone to puts the brake pedal see where it comes from.

In general I would agree, my only thoughts re this is that with older vehicles the chance of good quality OEM parts becomes limited so more obscure companies start supplying less than, shall we say "top quality parts".

 

[Rlbow43]

I think this is the end of this topic. I finally figured out that the brake line was not leaking. It was the bleed valve - which I thought was tight. I just happened to see the bleed valve bubble just a bit after putting some fluid in the master reservoir. Now both front brakes are not leaking. I did buy new crush washers for all hose connectors at each wheel, and I did anneal them. Once I hung the washers on a wire they heated up almost instantly.

I will post a new thread on my next brake problem - bleeding the brakes. It has it's own set of issues.

Thanks to all for all the help. It appears I will continue to need assistance...

 

[bugsymike]

I think this is the end of this topic. I finally figured out that the brake line was not leaking. It was the bleed valve - which I thought was tight. I just happened to see the bleed valve bubble just a bit after putting some fluid in the master reservoir. Now both front brakes are not leaking. I did buy new crush washers for all hose connectors at each wheel, and I did anneal them. Once I hung the washers on a wire they heated up almost instantly.

I will post a new thread on my next brake problem - bleeding the brakes. It has it's own set of issues.

Thanks to all for all the help. It appears I will continue to need assistance...

Ha, ha! "Yes sir we have found the cause of your problem, it is the nut loose behind the steering wheel"