Brake Pressure Sensor Installation

*Rick Ross* · July 11th, 2012, 1:54 PM

My current car (RT-40) will be my first with brake pressure sensors, and I am seeking advice and/or comments regarding the various installation options. I know that I can always install a "T" fitting into the front and rear lines, and then run short hoses to the sensors. I was also considering the use of stacked banjo fittings on each MC, with one banjo for the usual brake lines, and the other banjo directly supplying a line which goes to a pressure sensor.

I was also wondering how critical the sensor location is regarding the occasional need to bleed air out of the sensor supply line.

Any comments are appreciated.

*Swift17* · July 11th, 2012, 2:25 PM

Please see attached ...........

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*TimW* · July 11th, 2012, 2:36 PM

I use a double ended banjo (not a double stack) on the master and then bleed the line to the sensor upon installation. I usually don't have to bleed again unless there is a problem.

*Rick Ross* · July 11th, 2012, 6:19 PM

Quote:

Originally Posted by TimW

I use a double ended banjo (not a double stack) on the master and then bleed the line to the sensor upon installation. I usually don't have to bleed again unless there is a problem.

Tim,

Do you also use the double-ended banjo on the front brakes? On my car the two ends of the double banjo are used for the lines going to the individual front corners.

*TimW* · July 11th, 2012, 6:31 PM

Quote:

Originally Posted by Rick Ross

Tim,

Do you also use the double-ended banjo on the front brakes? On my car the two ends of the double banjo are used for the lines going to the individual front corners.

No, on the DB6 there is a mount in the bulkhead for a mounted T, so one line from the master to the T, then one line to the sensor. Each caliper has a line from the T. Same on the rear, though the T is not bulkhead back there.

Tiago Santos · July 11th, 2012, 7:22 PM

I was looking around for ideas a while ago (so I could make my own..) and Nathan at Radon had a similar manifold that was pretty cheap and should work perfectly. I remember thinking it would be cheaper to buy his than spend the time making mine, but I wanted an excuse to machine something

timos · July 11th, 2012, 7:52 PM

I just used the Russell banjo bolt with the integrated 1/8 NPT (IIRC) female thread in the head, and thread the sensor into it. Maybe I'm missing what you're after.

*Rick Ross* · July 11th, 2012, 11:31 PM

Quote:

Originally Posted by timos

I just used the Russell banjo bolt with the integrated 1/8 NPT (IIRC) female thread in the head, and thread the sensor into it. Maybe I'm missing what you're after.

That would work. Where can I find this mysterious "Russell" bolt?

timos · July 12th, 2012, 1:31 AM

Believe it or not, it's typically used as a Harley brake light switch adapter and can be found in some bike shops.

Summit fails to point out the 1/8" NPT part of this - must annoy a lot of folks thinking they're getting a normal banjo.

http://www.summitracing.com/parts/RUS-R40505/

or search "Russell R40505" on amazon or ebay for more description. 3/8-24 banjo with 1/8 NPT fitting. 10mm washers (why mix dimensions???)

I've had no problem with this on two Atlantics. No weeping, failures, ... the chrome part bugs me but lately I have been feeling like I should maybe chrome the engine and switch to a black leather driving suit with a kaiser helmet.

... oh yeah, for those in vintage organizations (SOVREN) that require brake lights on formula cars (I think this is silly, personally), this is way easier than plumbing in a T. Just buy this and a hydraulic brake light switch and you are done (except for wiring it into the rain light circuit).

*Rick Ross* · July 12th, 2012, 2:25 PM

Thanks, Tim......great info. Did you have any problems with sensor reliability when mounted in this manner?

timos · July 12th, 2012, 2:39 PM

So far no issues. I'm using a MyChron MSI style sensor which is fairly low mass, so it doesn't stress the banjo or the sensor. It's a little noisy, I don't know for sure if that's due to rigid mounting or other reasons. It doesn't matter for my purposes (driver coaching).

*Rick Ross* · July 12th, 2012, 5:10 PM

Hmm.....just pulled up the spec sheet for my Pi pressure sensors. Looks like they use 3/8-24 male threads instead of 1/8 NPT. So I would need an additional adapter to use the Russell banjo bolt. I'll see if I can find a male 1/8 NPT to female 3/8-24 adapter.

timos · July 12th, 2012, 5:44 PM

Check for clearance if your banjo points in an unfortunate direction...

Gary_T · July 12th, 2012, 6:37 PM

From what I've heard/seen the MSI pressure sensors (at least engine oil press) don't like solid mount and the vibrations.

What is the max PSI that we see on FC cars for brake pressures?

Thanks,

timos · July 12th, 2012, 6:43 PM

Good point. Yes, I would never do this for oil pressure, with MSI or VDO or any other gauge. Engines really vibrate!

tim

*Rick Ross* · July 16th, 2012, 10:26 PM

I found some 1/8NPT male to 3AN female adapters at Summit that I can use with the previously mentioned Russell banjo bolts. The plan is to just screw the pressure sensors directly down into the AN adapters and banjo bolts, thus essentially mounting the sensors directly to the master cylinders. We'll see how it works out........

Thanks to Tim and others for the good help.