Pressure in brake caliper

[crankcase]

Anyone know the Max (Billy-Ray) pressure generated by the master cylinder for front brake calipers ?
What I mean is the pressure in psi or bar pushing out the brake piston, not the clamping farce.
I'm guessing there isn't a fixed amount for all bikes and it varies quite a bit between models / cc's etc so just an average for a middleweight will do.
Don't ask why..............it's a long story.
Found nowt on the internet of any use.

Cheers,
Crank.

[coullstar]

Not a clue but if you really want to find out just plumb in a pressure gauge.

[crankcase]

Nae that simple I'm afraid.
I'm pressure testing the caliper off the bike.
Bikes at home and I'm offshore.
Mate asked for me on Visordown and was told 2500psi so will go with that unless anyone can tell me otherwise.

Thanks anyway.

[CBRXX]

Nae that simple I'm afraid.
I'm pressure testing the caliper off the bike.
Bikes at home and I'm offshore.
Mate asked for me on Pantsdown and was told 2500psi so will go with that unless anyone can tell me otherwise.

Thanks anyway.

http://www.scientific.net/0-87849-428-6/429/

[crankcase]

Thanks for the link Blackstorm but I can't view it.
Tells me "this operation is not allowed" then when I click the link to view the full paper it asks me to sign in with user name and password.
Clicked "get full access here" and it asks for $58 a month.
Being a true Aberdonian I'll pass on that I think.

Can I ask you to maybe copy and paste the info from the site and post it here ?
Be worth a if I ever meet you in person.

[RK6]

Ultrasonic Leak Test for Automotive Brake Caliper
C.H. Johnson1, a, E.A. Druschitz2,b A.P. Druschitz3,c
1CWU, 400 E. University Way, Ellensburg, WA 98926-7584, USA
2UM ROLLA, 1870 Miner Circle, Rolla MO 65409, USA
3INTERMET Tech. Ctr., 939 Airport Rd., Lynchburg, VA 24502, USA
acjohnson@cwu.edu, bedruschitz@gmail.com, cADruschitz@intermet.com

Keywords: Leak Path Defect, Ultrasonic Detector, Caliper Casting, Capstone Course.
Abstract. Leak path defects in brake caliper castings were observed and an efficient method of
detecting them was needed. The standard detection technique used a differential decay method at
pressures up to 1000 psi but this technique could not detect all of the leak path defects. The only
known method that could detect all of the leak path defects was a technique that used brake fluid,
and required pressures up to 3,000 psi. Because a fluid medium used to conduct this test,
regulations precluded the calipers from being used on a vehicle after the inspection process. This
was the motivation for a Capstone Project in the Mechanical Engineering Technology Program at
Central Washington University.
For safety and economic reasons, a nondestructive test which utilized acoustics was chosen. It
was decided that the main focus for this project would be the design of the fixture. The prototype
fixture was designed to utilize a toggle clamp and a backing plate (manifold) with O-rings. The
clamping system was produced at INTERMET Corporation. After the fixture was completed it was
sent to Central Washington University. To verify predictions, strain gauges were used at different
parts of the system during normal use. Then the placement of the acoustic listener was determined,
completing the test fixture.
In order to obtain a good seal (O-ring to cavity lip) the fixture required deflections less then
.0045” (as determined by tolerance stacking and O-ring deformation requirements). A magnetic pin
gauge was used to measure this displacement as it the fixture was pressurized to 82psi (available
shop pressure). To demonstrate the safety of the device, a strain gauge was mounted on the backing
plate to measure the farce being counteracted by the toggle clamp. The maximum stress on the
backing plate was approximately 10% of the material's yield strength (~ 36 ksi for A36 steel);
producing a safety factor of about 10. No more than 3750 psi was measured. The maximum strain
of the backing plate was 0.003 in/in. Upon completion, the fixture was sent back to INTERMET
Corporation where a production model was designed and implemented.
Introduction
This project was motivated by the need for a flaw detection system that would allow INTERMET
Corporation to check brake caliper castings for leaks before shipment. Current manufacturing
processes can result in as many as 1 to 5 rejected parts per 10,000 being produced. The subject
brake caliper is used on trucks and SUV’s totaling 900,000 vehicles per year, resulting in 3.6
million of these calipers alone produced per year. For economic reasons, it was also desired that no
parts be scrapped due to the inspection process.
The benchmark flaw detection system used a fixture to clamp the caliper, and fluid to pressurize
it. For the new system, a new set of requirements were created: 1)be non-destructive, 2)have a
cycle time of less than three minutes, 3) use 120V if necessary, and 4) use between 60 and 90 psi
air.
The project was used to support the senior capstone course in the Mechanical Engineering
Technology Program at Central Washington University [1]. The scope of capstone course design
effort would be narrowed down to the clamping system. However, the entire system would be
designed and a prototype fixture constructed and tested. The technical merit of this project focused
Copy,Edit and Printing deactivated. Original document has 4 pages
Full library access is here http://www.scientific.net/subscribe
Materials Science Forum Vols. 539-543 (2007) pp 429-432
online at http://www.scientific.net
© (2007) Trans Tech Publications, Switzerland
Online available since 2007/Mar/15
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the
publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 84.65.51.72-04/06/08,12:55:25)

[crankcase]

RK6 and Blackstorm you are both gentlemen

RK6 I'll buy you a too.

Jeez I'm feeling generous today.