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Brake fluid reservoir position
AndyGaskell - 29/1/18 at 06:10 PM

Im installing a remote brake fluid reservoir to a fiat 124 brake cylinder and just asking if the remote reservoir has to be placed higher than the master clylinder being gravity fed or is it pressurised and can be positioned lower? Im struggling to get a reservoir higher than the cylinder.

Thank you


voucht - 29/1/18 at 06:22 PM

Hi,
The reservoir definitely needs to be higher than the master cylinder, as it is gravity fed.
Hope that will help


AndyGaskell - 29/1/18 at 07:07 PM

I can get the reservoir above the cylinder but the pipes would drop sweep lower than back up. Is that acceptable or does the pipes all need to be above also?


voucht - 29/1/18 at 11:19 PM

The brake fluid always has to go downstream, as there is no suction from the master cylinder, nor pressure in the reservoir. If the brake fluid has to go up the pipes at one point, it will not work (it will not feed the master cylinder).

Can't you install a master cylinder with integrated reservoir, like the one from Ford Sierra (or a lot of other brands/models, I'm sure Fiat has some of this kind), without having to set-up a remote reservoir connected to the master cylinder with pipes and fittings?

I mean a master cylinder on which the reservoir clips, like on the picture below. Space above the master cylinder is really minimum with this set-up, and of course, it exists flat reservoirs (unlike this one) which are even less space-taking. Also, Wilwood makes "tandem" master cylinders with these kinds of clip-on reservoirs.

2012-11-11_ 16-37-09 by Sylvain ROIG, sur Flickr


AndyGaskell - 30/1/18 at 12:18 AM

Im moving away from the seirra cylinder for the fiat 124 as adviced by many for better brake feel. Problem is the 124 as standard has a remote reservoir


flanders - 30/1/18 at 08:27 AM

If the reservoir is higher than the M/C inlet, even if the feed pipes 'dip' below the M/C, gravity should still feed fluid to the cylinder but I wouldn't recommend it and it may be a Pain to do the initial system bleed, as you will need to prime the feed pipes. try and keep the reservoir and feed pipes higher than the M/C

Have a look at my post, you'll see how I fitted the Fiat M/C with remote reservoir http://www.locostbuilders.co.uk/viewthread.php?tid=210252


SJ - 30/1/18 at 08:32 AM

As long as the pipes aren't going way lower than the MC it will be fine. Just keep them as short as possible. As long as the exit from the pipe is lower than the entry gravity will push the fluid to the ends and you will have no issues with air getting trapped.


voucht - 30/1/18 at 09:25 AM

quote:
Originally posted by flanders
If the reservoir is higher than the M/C inlet, even if the feed pipes 'dip' below the M/C, gravity should still feed fluid to the cylinder

quote:
Originally posted by SJ
As long as the pipes aren't going way lower than the MC it will be fine. Just keep them as short as possible. As long as the exit from the pipe is lower than the entry gravity will push the fluid to the ends and you will have no issues with air getting trapped.


Yes, you are right about that, sorry for having been pessimistic in my previous post.

Specifically, no part of the feeding pipes should be higher than the brake fluid level in the reservoir, considering of course the minimum level of brake fluid in the reservoir.