Brake Fluid Reservoir "Upgrade"

[calw]

I'm about to start a quest, and would like any available advice. 

 

My late '68 1600 originally had single circuit brakes and a completely different setup around the pedal box and MC.  I've decided to switch to the later dual circuit scheme and have rebuilt a pedal box, added a new MC, all new lines, etc...  

 

The original reservoir was mounted farther aft and lower than later cars- right next to the upper pivot assembly in newer cars (the bracket location is shown in the photo in the blue oval.  Please ignore my unfinished wiring).  The "normal" reservoir with two bottom outlets for the two circuits and side outlet for clutch has the same hole spacing and will mount on the bracket, but the outlets are then lower than the MC, not gonna work...

 

I could mount the reservoir in the position used for later cars by making a bracket and drilling holes, but maybe there's another way...  Later cars, including the E30 and ? others have the reservoir mounted right on the MC.  No hoses to worry about, and no way to win originality awards (I'm past that when I switched to dual circuit brakes!).  There's an argument that puts the reservoir as high as possible, but millions of cars with the reservoir atop the MC can't be wrong.

 

Based on old threads this should work but may need different grommets to match the reservoir's outlets.  The spacing must be the same.

 

Does anyone have recent experience to confirm this or provide additional advice? 

 

Thanks!

Edited July 20, 2020 by calw
missing text

[Lorin]

Yes, you can do that. Almost any bmw reservoir through the 80's  (at least) will attach with the matching grommets. I did it on my last car.

 

 

[calw]

Thanks. 

 

To the junkyard!  (with an old MC in hand). I assume you mean that I need to get matching grommets for whatever reservoir I find, as the little plastic elbows are pretty small.

[AceAndrew]

You’re going to need a later master as well.  

[Lorin]

1 minute ago, AceAndrew said:

You’re going to need a later master as well.  

 

Thanks for the clarification, Andrew. 

 

When did the master cylinders change to a different size grommet ?

[AceAndrew]

e21/e12 generations.  Please pardon the brief responses, balancing a lot.

[Mike Self]

Why not use the dual reservoir that was fitted to the '68 2002s, which had the dual brake setup?  They came with a separate clutch fluid reservoir, so no extra outlet to plug.  And they sit right down on the master cylinder.  '02s didn't get the remote reservoir until second series '69's.

 

mike

[calw]

Thanks for the responses! 

 

Mike, I wasn't even aware of 69's having the reservoir on top, I'll look at that.  I'm wondering why the various changes.  Obviously cheapest is a single reservoir for everything, but it seems cheaper to also eliminate 2 hoses and put it on top of the MC, feeding the clutch via an outlet from a single reservoir there.  Clearly the technology isn't difficult.

 

Andrew, Are the holes in the cast iron body also different, or just the grommets?

 

 

[Mike G]

Here’s what Andrew has told me on this topic in the past. 
 

“ Also keep an eye out for an E21 or E30 brake fluid reservoir, when running a tii or e12 brake master cylinder, you can then ditch the fender mounted reservoir in favor of the E21/E30 piece that mounts directly onto the BMC.  ”

[rcf925]

On my 68 I went with E21 master with reservoir on top, And still have separate clutch reservoir both hooked up to low fluid light. I like having the clutch and brake fluid separate 

[FunElan]

My still single circuit '68 had the later master cylinder with the reservoir mounted into the bigger grommets (photo of stamping attached) and worked pretty well, but I developed a strange issue with pedal feel that I couldn't diagnose. I asked a shop to help, and gave them an NOS 1600 master cylinder and a standard 02 reservoir just in case. Pictured is the result - a plate that mounts to the stock location but moves the reservoir up a bit. Could be another easy solution to your predicament. 

 

(After I rebuilt the calipers, my problem went away)

 

[calw]

Rounding up this discussion-

34321114840 is the Brake Fluid reservoir used in E21, E30, and other models. It has the same spacing between holes as the 2002 Master cylinder.  But, it's outlet holes are a much larger diameter, about the same as the outer diameter of the grommets on the 2002 MC. The newer matching MC has much larger diameter inlet holes and a matching grommet, 34311160133.

 

So, using the 34321114840 reservoir with the 2002 MC will NOT work, as Andrew already reported.  It would work if one could create a sturdy, low profile, brake fluid proof, leakproof "funnel" part to insert between the MC and reservoir.  Not likely... 

 

I assume that a later MC will mount on the 2002 booster and allow that reservoir to be used.  Regarding the early 2002 having a reservoir atop the MC, that part is probably 34321103476, which presumably has small diameter outlets that match the standard MC (all conjecture, I've not seen one in person).  This part is probably very hard to find.

 

For my situation, I'm going with the FunElan solution because it adds no new holes in the body,and I have the parts.

[irdave]

I think I have some of the large elbows and probably some fancy brake reservoir line left over sitting here if you want it.

 

And I'll grab a couple of pictures of my set up for you in the morning.

[calw]

Thanks, Dave. I'll PM