Are banjo bolts grade 8?

[clhyer]

Good morning folks,
I have put new calipers and brake lines on my Duster. One side continues to weep a little brake fluid at the line to caliper connection. Yes, the copper washer are there, you can see them both (one between line & caliper, one between the bolt head and the line. I have really tightened and retightened it. I am afraid to get a longer wrench on because I don't want to break off the banjo bolt.
Have I overtightened it and need to try a new copper washer?
Any other suggestions?
Thanks,
C

 

[chasduster]

I always try to make sure The washers are the same exact diameter as banjo bolt....some are a little larger and I have had them leak on me..... Also if you happerned to put a new caliper or line on make sure there is no inperfections in the castions where the fluid can seap out........ Other than that..... No there are no grade 8 bolts that I am aware of and they will take allot of torque to keep from leaking

 

[clhyer]

Thanks for your response. I have already tightened it with the old "wrench in wrench" trick. I guess my next step is to disassemble and check for those imperfections and look for a new set of washers.
Thanks again,
C

 

[RustyRatRod]

Make sure the bolt is not bottoming out. I've seen that a couple of times. They are only grade 5 so be careful puttin the mojo on um. They are only made for fluid transfer, not to really hold anything of any consequence. You might try running a file over the flat surrounding the hole and making sure it's flat. Sometimes small burrs and imperfections can cause a leak.

 

[Revhendo]

Get new washers and put anti-sieze on all mating surfaces and the bolt threads. Barring mucked up grooves on the caliper mounting face, I've never had a leak.

 

[clhyer]

Thanks guys.
C

 

[RedFish]

Last line I bought from Advance auto parts included washers that wouldn't even fit the bolt. ID too small. Reused the original washers and it didn't leak. Used washers will have grooved sides and smooth sides. They must be arranged properly.

 

[funwithfuel]

Sometimes, I have seen where the new copper seal rings are too hard . The problem is they won't crush. If you have access to a fuel injection pump shop or truck shop nearby take your seal rings to them as samples. Tell em you want the same ID rings. The ones they commonly use for turbo oil supply and fuel are much softer than the junk rings that come in the rebuilt caliper box. Of course this is last option after everyone else's ideas have been tried. I believe everyone else has given you good solid guidance. One last thing is be sure to check the radial grooves in the head of the flex line , any damage there and you'll never seal properly. Just my 2cents

 

[FISHBREATH]

One "trick" I learned long ago is to use a piece of plate tempered glass as a base under fine sand paper or emory cloth when surfacing parts. The glass is very flat.

 

[bohica2xo]

Sometimes, I have seen where the new copper seal rings are too hard . The problem is they won't crush. If you have access to a fuel injection pump shop or truck shop nearby take your seal rings to them as samples. Tell em you want the same ID rings. The ones they commonly use for turbo oil supply and fuel are much softer than the junk rings that come in the rebuilt caliper box. Of course this is last option after everyone else's ideas have been tried. I believe everyone else has given you good solid guidance. One last thing is be sure to check the radial grooves in the head of the flex line , any damage there and you'll never seal properly. Just my 2cents

A more common problem than many realize. Dead soft copper is a pain in the butt to stamp, and burrs easily. Harder copper will stamp nicely, but it does not deform to seal properly.

So, when someone goes to China for washers, they ask for cheap. Half the time the purchasing agent does not have a clue about what that washer actually does... So you get half hard copper, stamped & flattened. The cold working of the manufacturing process cold works it to nearly full hard. Much lower manufacturing cost, but the part is not to spec.

This is easy to fix. Copper anneals readily over 750f. Lay the washers down on a firebrick, and grab the propane torch. Heat them until they get to red hot, then walk away and let them cool. Dead soft now. They will have a thin film of black oxide, which you can wipe off with steel wool.

Take an old pair of washers from a used caliper. Anneal one. Now try to bend each one with your fingers.

B.

 

[clhyer]

A more common problem than many realize. Dead soft copper is a pain in the butt to stamp, and burrs easily. Harder copper will stamp nicely, but it does not deform to seal properly.

So, when someone goes to China for washers, they ask for cheap. Half the time the purchasing agent does not have a clue about what that washer actually does... So you get half hard copper, stamped & flattened. The cold working of the manufacturing process cold works it to nearly full hard. Much lower manufacturing cost, but the part is not to spec.

This is easy to fix. Copper anneals readily over 750f. Lay the washers down on a firebrick, and grab the propane torch. Heat them until they get to red hot, then walk away and let them cool. Dead soft now. They will have a thin film of black oxide, which you can wipe off with steel wool.

Take an old pair of washers from a used caliper. Anneal one. Now try to bend each one with your fingers.

Wow, what an interesting post. Thanks:cheers:
I was concerned about trying to file or smooth out either the caliper or the line. How would you do that without the risk of metal filings getting in the system?
C

 

[bohica2xo]

Gravity is your friend. Turn the caliper up so the file is under it. You should not need to remove much.

Actually I would not file on a seal surface unless there is visible damage. A file will leave linear marks that are more prone to leak than concentric marks from rotating tools that made the part.

The line can be easily removed & cleaned - or you can just wrap a rag around it & step on the brakes to flush it... A bit of scotch brite, gripped so that each surface of the banjo is under the abrasive & twist the line so that the scratches are concentric to the bolt bore is the way to go for cleaning the line sealing surface.

I would start with a soft set of washers & all the force you can muster by hand on a single box end wrench to tighten the bolt. Wet the threads & the washers with brake fluid when assembling things.

B.