Technical information on brake components – calipers, brake fluid, master cylinders, slaves, brake lines…
Brake caliper seals for automotive fluid – for Clevland calipers (same calipers on G109A & Dimona H36)
Part# info on bag:
BS218 X 10
from Halray Brake Reconditioning
7/5 Krauss Avenue South Lismore
02 6621 4029
Caliper Piston Seals – original Cleveland items are for aviation brake fluid, but o/ring seals for automotive brake fluid are available. (RJW has some of these – property syndicate 0807)
Brake Calipers – Cleveland 30-9 (FFN stamped 389)
Bleed nipples on G109 calipers – spanners sizes: 7/16″ & 1/4″
Brake Master Cylinders – Grimeca
Brake discs – cast iron – G109 & H36 probably same
Dimona H36 Brake Fluid – From the manual.
7.3 BRAKE FLUID:
The Brake Fluid used is SAE J 1703 (SAE 70 R3) or FMVSS 116 DOT 3. The aircraft MIL-5606 is NOT to be used (RED). When adding fluid, pay attention the fluid does not spill over on painted surfaces. Insure the cap for the reservoir can vent to the atmosphere. Before adding Brake Fluid, attempt to determine why fluid is needed.
So, it appears likely that some H36 Dimonas brought to Australia ex-Thai airforce had been changed over to aviation milspec brake fluid. Something to aware of..
Sent: Saturday, August 08, 2009 6:37 PM
Subject: Re: More on M.S.
Nigel Baker wrote:
Check the bore of the Cylinder carefully for corrosion. That will strip the seals fast if it has. As it is running normal car brake fluid there is a likelihood of corrosion. If fine it can be honed. If deep it is stuffed and fitting new seals will only delay the inevitable as the new ones will leak soon too.
Also check the slaves for the same problem. The normal aircraft hydraulic is better in that it doesn’t retain moisture like the car stuff. If you change it over by changing seal type don’t forget to change the hose as well (it is due every 5 years anyway !!).
If changing to aviation hydraulic fluid (probably not a great idea in our case as all the others are automotive) you’d also have to change the caliper seals.
Overcome hygroscopic problem by changing fluid every couple of years.
I meant if changing all the seals don’t forget the hoses as it is easily done. Yes bleeding the system each year to replace all the fluid thus flushing it makes a big difference.
So when was the last time you guys actually did that as an item for an annual inspection ? cause that’s how often you need to do it in your environment and yes in a car too.
I rest my case.
I’ll stick with aviation fluid I think and yes I bled mine a couple of years ago even though it is “real” oil.
Does the 5 years also apply to braided stainless brake lines with teflon core?
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G109 uses Grimeca master cylinders which are difficult to obtain. It should be possible to find a compatible seal, and if the cylinder is pitted one can have a stainless sleeve fitted.
Russell, by any chance could you determine the Grimeca master cylinder Model number ? I would be ever so grateful if you could identify it as I am grounded . – Michael Price (MP) +1-404-395-3218