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View Full Version : Looking for some brake reservoir advice



shackf16
06-25-2022, 12:56 PM
Hey gents!

I'm slowly making progress towards getting my Mk-3.1 back on the road after a pretty significant overhaul, and need some advice on my brake master cylinder reservoir options. I upgraded the entire brake system on my car - Brembo 13" front kit, Baer 13" rear kit, 94-95 ABS unit, and swapped out the vacuum booster for a hydroboost unit from a '96 GT with master cylinder. I have everything in place, but I need to run a remote reservoir setup if I ever want to service the brake fluid without removing the body. I've read countless threads on different reservoir setups, and while most of them have been associated with the Wilwood pedal box setup, they have been enlightening. I am running the stock '90 Fox-body pedals, and have modified the brake pushrod as well as the 1/2 tube in the pedal box to get everything lined up and working properly.

So, a few questions for the experts. What is the minimum volume you are comfortable with in the remote reservoirs? (I haven't been able to find the quantity of the original direct mount reservoir, but will probably just check the old one with a measuring cup.) One set I was looking at only had 1.1 oz per side in a twin setup. That seems like a very small amount in my mind, and would probably take forever to bleed the brakes for the initial setup. I love the Tilton 3-in-1 low profile unit (TE 72-578), but I am only looking for a twin reservoir since I am using an old-school cable clutch. Unfortunately Tilton doesn't seem to make a 2-in-1 low profile reservoir option. That Tilton triple reservoir has 6 oz and 4 oz capacities for the front and rear, which really makes that 1.1 oz unit sound WAY too small. I looked at a Jamar Performance RR-1200 Dual Remote Reservoir but it doesn't list the quantity anywhere. Does anyone know what the volume in each reservoir is for that unit? It seems to be the same as the old CNC unit that FFR used to offer? I am also considering just getting 2 individual see thru plastic reservoirs from Tilton and figuring out a mounting option as that would be the cheapest while allowing me to see the quantity level without opening the lids. Those hold 5.3 oz each which seems reasonable.

I'm planning on mounting the reservoirs on the firewall, either running the hoses around the footbox or possibly through the footbox as I saw someone else had done and it looked very clean. I'll consider running them forward and mounting on the driver's F-panel as that is the shortest distance from the master cylinder, but I need to ensure I have sufficient height relative to the master cylinder ports.



I appreciate any advice you guys have on the quantity of the reservoirs, mounting locations, and even specific units that you have used. I attached some pictures that show the new billet MC adapters from Lodestone Billetworks, the old and new front and rear brakes for comparison, and the old vacuum setup that I drove with for a few thousand miles before I tore the car back apart.

Cheers,
Shack

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CraigS
06-27-2022, 06:20 AM
That is interesting looking at capacity. It is obviously important but I don't think I have ever seen a spec. Can you find the specs on the triple setup you like but don't need? If not I'd probably go by dimensions vs actual volume. OTOH the Tilton clear ones you mention would be a great setup.

egchewy79
06-27-2022, 06:44 AM
how much room between the cap and the body? you could consider an angled funnel if you have a bit of clearance under the body.

PG_Cobra
06-27-2022, 08:38 AM
I modified the cover panel to add a removable cover that takes a few seconds to remove with the wheel off. The entire panel is also removable with Dzus fasteners. On my Mk1 there was no space to bend the brake line using the Ford or similar MC so I installed a Chrysler LeBaron/New Yorker MC with left exits. Not the prettiest metalwork but it is well clear of the wheel and does the job.
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Ted G
06-27-2022, 10:00 AM
I actually used the FFR reservoirs and added a third. I squeezed them together by stacking them.

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shackf16
06-27-2022, 12:51 PM
The Tilton triple setup has 6oz, 4oz, and 2oz reservoirs. It looks like some of the Wilwood single reservoirs have 4oz capacity, so I am going to target nothing less than that, with a little more a bonus. Once everything is bled and buttoned up then higher capacity in the reservoir is really just in case of a leak in the system.

I haven't put the body on since I did the hydroboost conversion, but it was pretty tight with the vacuum booster and I think it's worse with the new setup. Like barely enough room to get the cap off - no way to get a funnel in there! I'd rather work with a remote setup than have to use a pump to push fluid into the stock setup, which adds a layer of safety having completely separate reservoirs in case of a leak in one system. I know the factory reservoir has a divider in the lower portion, but if running hard on a track then I would think a bunch of that might splash into the adjacent area.

Thanks for the input gents - I'll post more pics once I have my remote reservoirs installed.