Brake connections...

[Graham]

Hi Guys, Merry Christmas to you one and all.

I need some advice.

I'm stripping all the kit off the car to:

A) get a better understanding of how it all goes to together and
B) to paint the monococque.

So, two questions: What I want to know is when I reconnect all the brake lines back together, should I use PTFE tape on the threads, or just tighten them up with nothing???

And, When I reinstall all the suspension (wishbones etc...), is there a particular torque value that I should be going to, or do I tighten until my knuckles turn white, and should I use a thread lock fluid even though all the nust are nyloc?

Thanks in advance for your help,

Graham.

 

[Simon]

Graham,
If the nylocs have been used (ie they have been tightened so the thread cuts through the nylon), you should (for safety's sake) replace them all with new ones. They are supposed to be one time use only afaik, although people do use them several times. I always worry about their security on safety critical items (suspension especially) I'm sure Fran will pitch in with torque values, I would stick with what the mfr recommends.
I don't think you should use ptfe tape on brake lines.
Simon

 

[Graham]

Simon,

thanks for that. Time to get some new Nyloc's then!

Cheers,

Graham.

 

[Phil]

Graham:
I have had issues with teflon tape , small strands coming off and entering the system. Look for some teflon based sealer either in a tube or can with a small brush. We get it here from any parts supplier.
Lock nuts are cheap, and as Simon said have done their job so replace them, if you are unsure of the torque values for the fasteners there are tables you can look up for recommended torque on specific sizes.
I am assuming that you are using the sealer on pipe threads in your system, and it will work really well. The double flared parts of the system should be assembled clean and dry and the threads should go together easily. Use a flare nut wrench so as not to round out the nuts and don't over tighten, if they leak there is a problem and replacement or cutting and re-flaring may be in order.
Merry Christmas
Phil

 

[Brett James-McCall]

Graham,
Toolstation do Liquid PTFE

Brett

 

[Darnel A.]

Use nothing. The threads don't do the sealing, the Flared tube seals against the tapered seat. If it's leaking past the threads, you have a problem to fix, it won't hold brake pressure..

Darnel

 

[Graham]

Use nothing. The threads don't do the sealing, the Flared tube seals against the tapered seat. If it's leaking past the threads, you have a problem to fix, it won't hold brake pressure..

Darnel

Darnel, that makes sense to me,

Thanks all for your input!

Graham.

 

[Jonathan Strain]

Darnel is not completely correct. You have at least 4 pipe threaded conections that do need teflon sealant. There are right angle adaptors on each of your brake cylinders that are pipe threads. You may also have some pipe thread adaptors at the connection between the rear flex lines and the hard lines.

You should not use sealant on any flare fittings. It should be easy to recognize the flare fittings. Those are on the end of all the hard lines. All of the hard lines should have a fitting that will spin on the line and that should push the flared end of the tube into a conical seat.

In summary if there are matching cones that seat do not use teflon paste. If there are not any cones and the threads make the seal use paste. If you skip the paste on the seals that need it they will leak.

 

[Jac Mac]

Use nothing. The threads don't do the sealing, the Flared tube seals against the tapered seat. If it's leaking past the threads, you have a problem to fix, it won't hold brake pressure..

Darnel

+1.
Now on the RCR there was one fitting somewhere in the system that some builders had not followed assy instructions on that was causing a leak... Think it might have been Deane Lampe who raised the issue... they had tried to fit a pipe connection straight to a junction point IIRC without the supplied adapter & as a result got a fitting & thread mismatch + leak. Might not be the case on your car, but if you get a leak that just wont go away that might be the problem area..

 

[Darnel A.]

Guys,
The problem is there are too many types of fittings! If it is straight thread, then it should have a crush washer, so nothing is used on the threads. If it is a tapered thread (NPT), then a liquid teflon should be used, because there is metal to metal contact and sealing between threads. I never use tape because a piece can break off and travel into the system.

That's my story and I'm sticking by it!
Darnel

 

[DARREN]

The thread sealant we always used in F1 was Loctite 572 hydraulic thread sealant. You should be able to get it in any motor accessory shop. Just a little drop on the thread and job done.

D.

 

[Graham]

One question and so many answers....

Sooooo....

I've covered the bases. I agree that with a hard line and flare, use nothing, as the thread isn't making the seal. Otherwise I'll use some Loctite 572....

But seriously guys, I don't know what I'd do without all your help,thanks and a.....

VERY MERRY CHRISTMAS TO YOU ALL!!
:2thumbsup::2thumbsup::2thumbsup::2thumbsup:

Graham