Leaky front calipers/SS braided line- Copper Crush Washer??
04-23-2007, 01:56 PM
#1
Melting Slicks
Thread Starter
Leaky front calipers/SS braided line- Copper Crush Washer??
Issue: leaky SS braided line to front driver caliper.
Culprit: copper crush washer? uneven caliper surface? stupidity?
Started this issue in Bob's custom vert thread (since he just did his brakelines) hoping for a quick remedy proving my stupidity to be the cause. I think we have an idea of what is going on, but it is also my understanding that others have the same issue, so please chime in with your problems or solutions.
Culprit: copper crush washer? uneven caliper surface? stupidity?
Started this issue in Bob's custom vert thread (since he just did his brakelines) hoping for a quick remedy proving my stupidity to be the cause. I think we have an idea of what is going on, but it is also my understanding that others have the same issue, so please chime in with your problems or solutions.
I have all new SS lines and SS braided hoses to the calipers. Installed my hydro unit and new MC. Took a few hours but got the hard lines to stop leaks at the prop valve. (PIA) My big problem is, I got 4 new (rebuilt) o-ring calipers from VBP powdercoated. I can only hope they test the calipers for leaks before delivery. I have a leak where the SS braided hose meets the front driverside caliper. Appears there might be a very small divot/uneven surface at the 9 o'clock position on the caliper surface. It is my beleif that this is causing the leak to occur. The SS braided kit came with copper crush washers but those don't stop the leak either. I'm to the point where I am afriad to torque it down too much. Tried two copper crush washers, no luck still leaking. Finally put a copper washer then a larger SS washer then another copper washer and the leaking stopped...i think. The larger SS washer puts even and equal pressure on the copper washer against the caliper. The copper should conform and fill in that tiny divot.
Anyway, I have a lot of time grinding and painting into this caliper. If it doesn't leak tomorrow should I leave it the way it is? Is there another trick to get it to seal correctly? O-ring? gasket? Do I insist that VBP take it back and send me a new one? Remember that once I have the hydro unit up and running I assume it will apply more pressure to the lines, what fix can withstand that pressure? I want to do this right and remove any doubt of failure. Everyones advice is appreciated. Please PM me or e-mail me your thoughts so not to sidetrack Bobs thread. (doogie1101 at hotmail dot com)
This is the stupid SS braided hose that is leaking at the red caliper.
Looks trick eh?
Anyway, I have a lot of time grinding and painting into this caliper. If it doesn't leak tomorrow should I leave it the way it is? Is there another trick to get it to seal correctly? O-ring? gasket? Do I insist that VBP take it back and send me a new one? Remember that once I have the hydro unit up and running I assume it will apply more pressure to the lines, what fix can withstand that pressure? I want to do this right and remove any doubt of failure. Everyones advice is appreciated. Please PM me or e-mail me your thoughts so not to sidetrack Bobs thread. (doogie1101 at hotmail dot com)
This is the stupid SS braided hose that is leaking at the red caliper.
Looks trick eh?
you know i looked at those crush washers and the caliper fitting on my car......the hose seats it self at the bottom of the threaded nipple inside the caliper on the machined inverted flare.....so the crush washer does nothing to seat the hose.....so what i am saying is that building up the washer actually increases the distance of the "seating" surfaces and will work against you...i would go the other way and use only one washer and keep seating and reseating the hose. SS is really hard to seat and it takes more effort then regular steel.... i would even try tightening it down by hand using your fingers without a washer in it and the see how much space you have between the caliper and the hose....perhaps on that side the tolerances are poor and the crush washer is preventing a tight seal.
Thanks bob. I noticed the nipple on the hose but couldn't manuver my big head inbetween the A-arms to look into the caliper to see if there is an inverted flare in there. Makes sense that there would be.
I'll give the washerless method a shot tonight.
So in reality the caliper surface sealing to the hose nut is really just a back-up plan if the flare ends up failing, interesting. So much for the back-up plan.
Thanks for your insight
I'll give the washerless method a shot tonight.
So in reality the caliper surface sealing to the hose nut is really just a back-up plan if the flare ends up failing, interesting. So much for the back-up plan.
Thanks for your insight
Bob,
great job - you're almost back on the road.
68NJConv454,
Could you start a new thread about that brake line leak problem ? I have the same problem on my front left. The spot face is not 100% clean and I have to use two washers to stop the leak. I'll try it without washer, that should actually work ..... It looks like it's supposed to seal on the flare surface....
great job - you're almost back on the road.
68NJConv454,
Could you start a new thread about that brake line leak problem ? I have the same problem on my front left. The spot face is not 100% clean and I have to use two washers to stop the leak. I'll try it without washer, that should actually work ..... It looks like it's supposed to seal on the flare surface....
If I understand correctly and visualize in my head...there is a primary mating surface and a secondary. The primary connection is at the flare. The flare is on the inside of the hose end and fits inside the inverted flare inside the caliper hole. That seals the fluid.
Then you have the surface where the crush washer sits. This is the secondary mating surface. I think what Bob is saying is this crush washer & surface is there so you don't crank down and tighten the flare too much.
The copper crush washer gives you some lee-way and flexibility as I'm sure every caliper/line has different tolerances and gap depending on whether you use stainless or regular lines.
Am I on track?
Then you have the surface where the crush washer sits. This is the secondary mating surface. I think what Bob is saying is this crush washer & surface is there so you don't crank down and tighten the flare too much.
The copper crush washer gives you some lee-way and flexibility as I'm sure every caliper/line has different tolerances and gap depending on whether you use stainless or regular lines.
Am I on track?
Last edited by 68 NJConv 454; 04-23-2007 at 02:00 PM.
04-23-2007, 02:11 PM
#2
Drifting
Only the rear calipers use the internal flare and seal the end of the hoses brake lines.
The front calipers do not use the internal flare. The only seal is the copper washer. The washer needs to be replaced anytime the hose is removed.
A while back there were some front calipers that had the sealing surface machined crooked. The only fix was to send them back to be replaced/repaired.
Mike
The front calipers do not use the internal flare. The only seal is the copper washer. The washer needs to be replaced anytime the hose is removed.
A while back there were some front calipers that had the sealing surface machined crooked. The only fix was to send them back to be replaced/repaired.
Mike
04-23-2007, 02:23 PM
#4
Melting Slicks
Thread Starter
Only the rear calipers use the internal flare and seal the end of the hoses brake lines.
The front calipers do not use the internal flare. The only seal is the copper washer. The washer needs to be replaced anytime the hose is removed.
A while back there were some front calipers that had the sealing surface machined crooked. The only fix was to send them back to be replaced/repaired.
Mike
The front calipers do not use the internal flare. The only seal is the copper washer. The washer needs to be replaced anytime the hose is removed.
A while back there were some front calipers that had the sealing surface machined crooked. The only fix was to send them back to be replaced/repaired.
Mike
Not what I wanted to hear but if its the only fix then so be it. I'm a little skeptical with the array of washers I have on it now for a proper seal under opperating pressure. You see how pretty I made it? All that time lost.
04-23-2007, 02:39 PM
#5
Race Director
i actually have a stock one on the bench at home with the hose still connected to it....if you need me to tonight i can take it apart on the bench and actually measure things and we can see if the depth of the female end is greater or less then the the length of the hose end to see if they can bottom out or not
04-23-2007, 02:45 PM
#6
Melting Slicks
Thread Starter
i actually have a stock one on the bench at home with the hose still connected to it....if you need me to tonight i can take it apart on the bench and actually measure things and we can see if the depth of the female end is greater or less then the the length of the hose end to see if they can bottom out or not
Just spoke to Steve at VBP tech and he knew right away before i even told him about the divot that every once in a while there is a small dent that causes the leak. He said the only fix it to get a new caliper or machine that one. So I'll look at it tonight since I have to take it off the car anyway. I'll let you know if measurements are needed.
But I will probably overnight it to Steve at VBP tomorrow so he can machine the one that I customized properly and send it back to me without me having to recustomize a new caliper from them. Just a PIA that I paid enough money to avoid.
Thanks for your help
04-23-2007, 10:10 PM
#7
Le Mans Master
Thanks Bob. I'll let you know tonight.
Just spoke to Steve at VBP tech and he knew right away before i even told him about the divot that every once in a while there is a small dent that causes the leak. He said the only fix it to get a new caliper or machine that one. So I'll look at it tonight since I have to take it off the car anyway. I'll let you know if measurements are needed.
But I will probably overnight it to Steve at VBP tomorrow so he can machine the one that I customized properly and send it back to me without me having to recustomize a new caliper from them. Just a PIA that I paid enough money to avoid.
Thanks for your help
Just spoke to Steve at VBP tech and he knew right away before i even told him about the divot that every once in a while there is a small dent that causes the leak. He said the only fix it to get a new caliper or machine that one. So I'll look at it tonight since I have to take it off the car anyway. I'll let you know if measurements are needed.
But I will probably overnight it to Steve at VBP tomorrow so he can machine the one that I customized properly and send it back to me without me having to recustomize a new caliper from them. Just a PIA that I paid enough money to avoid.
Thanks for your help
... I on the other hand will receive the "I don't give a flying &%^&" attitude when I return my calipper to AutoZone.... "here's your replacement calipper, sorry about all the time you spent painting the pos we sold you"....
04-23-2007, 10:30 PM
#8
Melting Slicks
Thread Starter
Smaller companies (smaller than Autozone) are usually more cooperative when you mention a car club aka corvetteforum b/c they don't want to hurt their business and will offer better customer service than the average Joe.
Unfortunately Autozone will likely take your caliper and hand you the next on on the shelf...and repeat as necessary until you get one that works.
Good luck
04-23-2007, 11:01 PM
#9
Race Director
ok just did a bob test...the hose end is definitely an inverted flare...the caliper end is not.....it looks just like the bleeder ports....i removed the crush washer cleaned everything up with brake clean and then put grease on the end of the hose fitting and screwed it down....removed it and there was not grease on the bottom of the caliper ...the crush washer is the seal...
04-24-2007, 03:09 AM
#10
Melting Slicks
Thread Starter
ok just did a bob test...the hose end is definitely an inverted flare...the caliper end is not.....it looks just like the bleeder ports....i removed the crush washer cleaned everything up with brake clean and then put grease on the end of the hose fitting and screwed it down....removed it and there was not grease on the bottom of the caliper ...the crush washer is the seal...
Bob test is quick, simple and effective I took the caliper off, measured everything and the hose end is just a hair shorter then it needs to be to make contact with the inverted flare in the caliper. Either way both the hose and caliper have conflicting flares and would never seal even if they did contact eachother.
Therefore I concur and validate the Bob Test
Here are a few pics from tonight.
BTW, I am sending my caliper to VBP tomorrow so they can either resurface the sealing area or replace the back half of the caliper with a new powdercoated half so I won't have to redo my lettering.
I've received info that VBP does air test them before they go out the door but I understand that a few can slip by or results varry.
I am including my SS line and washer with the caliper so Steve at VBP can check the combination out.
This is my brain before dinner and hungry for a solution... copper crush washer against caliper surface, large SS washer to evenly distribute load and sandwhich the first crush washer against the caliper surface and then another coper crush washer to conform to the SS hose bolt surface. I tried using only two copper crush washers to fill the divot on the caliper surface but when torqueing them down they would offset and not overlap perfectly.
This is the inverted flare on my SS braided hose that fits into the caliper.
This is the port in the caliper where the SS braided hose threads into.
May be tricky to the eye but the flare in the caliper is the same as the SS hose, both inverted therefore they would not mate even if they could touch.
I boxed in the slight divot that I beleive to be the culprit of the leaking. Steve at VBP told me that even a slight imperfection to the eye can cause leaks. I hope to have the repaired caliper by end of week.
Thanks Bob for your efforts
04-24-2007, 04:37 AM
#11
Race Director
The "flare" or angle that is seen in the caliper is simply from the point of the bit used to create the hole (similar to end of drill bit). No seal surface was intended.
