Emeraude brake master cylinders

[ffg]

We have a possible issue with one of our master cylinders, which might need replacing or servicing at some point.

Does anyone know where these items originated, and whether spares/replacements are obtainable?

I heard that some of the brake parts came from 1950's Renaults - the drum brake slave cylinders. That makes sense, given the aircraft's age and origin.

The master cylinders are bolted to the cockpit floor with four mounting bolts, if that helps to identify them.

Thanks

David Pick

[mb2]

We had a similar problem a couple of years ago. The slave cylinders can be overhauled by Airworld but the Masters are not servicable, so we bought a new one, again from Airworld, about £80.00 at the time.
Fitting is easy, bleeding them was not.

Hope this helps

Mark B

[Domo1977]

Have you tried Pete Smoothy at Airworld UK?
Your installation sounds similar to our Jodel, we worked out that it uses some old Citroen or Renault brake parts.

edit just noticed that mb beat me to it!
agree if the brakes are the same as our Jodel then they are a pain to bleed and can lead you into thinking you have a bad cylinder when it's actually just air in the system.

[gasax]

I had an Emeraude years ago and had to refurbish the brakes.

From memory the slave cylinders were very easy to replace with Mini rear cylinders - minor fettling of the back plates.

The masters were much more difficult, one of the local factors let me rummage through their stock until I found a slightly over size set of seals - unfortunately I cannot remember what from. 5 minutes with an adjustable reamer and they were sorted.

Probably much easier to buy replacements - but that care over the ratio of sizes between the master and slave, it is quite easy to make them very powerful which might not be such a good idea.

[ffg]

Thanks, gentlemen.

I had already had a look at the Airworld website but the master cylinders shown (remote reservoir type) look nothing like our cylinders. I haven't actually spoken to Pete yet but will do so.

What's actually happening is that the LH cylinder operates with the piston about halfway into the cylinder, but the RH cylinder is much further inside - they both work fine, but the pedals are at different positions as a result. I don't think the RH needs bleeding as there is no sponginess of the pedal.

I rather presume there is a spring inside the cylinder which should return the cylinder to the top of its travel? in which case the RH cylinder is probably partially seized and can't return, or the spring is broken.

Quite happy to replace both cylinders if I can find replacements which fit.

Thanks for your help.

[Mike Fawdrey]

If you are having trouble bleeding brakes one solution would be to obtain a Gunson Eezi bleed kit. In years gone by I had a motorcar which was very difficult to bleed
This kit consists of a a bottle holding brake fluid which screws on top of your normal fluid container.
It is then connected to an inflated tyre by a valve connexion.
This pressurises the system and forces brake fluid past any airlock once a bleed valve is opened

[Rob Swain]

Best way to bleed aircraft brakes I've found is with a piece of clear tube, and a 100ml syringe. Fill the syringe with fluid, attach this at the caliper end to the bleed nipple and then just push the fluid back up the system.

Helps if you have somebody keeping an eye at the master cylinder / reservoir end to make sure you don't over fill it!