Brake clutch reservoir loss of fluid

[Roly]

Yesterday while at a car show and with the bonnet open, I happened to check the fluid level in the reservoir. I was surprised to find it had dropped by about 1.5” in both the brake and clutch receptacles. I can only assume that something is unhappy inside the reservoir at the bottom. 
 

i have double checked the rest of the hydraulics and all is dry at wheel cylinders and clutch slave and pipe work. 
 

any thoughts?

Thanks 

Roly

[BlueTR3A-5EKT]

Usual culprits for fluid level drop without any visible leaks is the extra fluid taken into the system pipework and cylinder(s) for self adjusting clutch slave cylinder and the two front calipers.

How worn are the front disc pads?

[RogerH]

When was it last topped up?

 

Roger

[Roly]

Brake pad and callipers were new about 3 months ago. That was when it was last topped up. 
 

my concern is that the clutch fluid level in its cylinder was exactly as low as the brake fluid level. So fluid must either be passing between the two receptacles or having a common leak at the outside at the underside. This area is dry but dirty. 
 

i have obviously topped it up and will monitor. I have white kitchen roll underneath the reservoir to see if anything is dripping. 

Edited September 3, 2023 by Roly

[Lebro]

The two levels are separated by a thin cylinder which is soldered to the base of the resovoir, (the cylinder it's self is formed from a flat sheet, formed into a cylinder, & soldered up the seam. If any of the joints separate then the brake & clutch fluids can combine.

I had to re-solder mine.

Bob

[Roly]

Thank you Bob. 

[Ian Vincent]

FWIW, in my reservoir, the clutch part is a separate tube that is clamped to the base of the main cylinder by the outlet union. If you have a thin wall socket you can unscrew it. 

Rgds Ian

[Lebro]

Yes, you are correct, but that tube has a soldered seam running up to the top, any split in that will allow the fluids to mix. (Mine was split, which is how I know !)

Also where the union clamps the inner tube to the base has to be completely sealed to avoid loss of fluid.

Bob

[Roly]

Having inspected wheel cylinders, pipes and clutch slave cylinder and master cylinders, all is dry. The reservoir is dirty so I shall monitor. All is back together. Now at pub. 

[rcreweread]

Have you got a brake servo fitted by any chance?

Cheers Rich

 

[Roly]

No servo. 

[RobH]

Did you look at the brake light switch?  Those have been  known to leak. 

[Roly]

Ah. Thanks. 
I put some kitchen roll under the reservoir yesterday, and today it is slightly discoloured. I have replaced with fresh piece and will check tomorrow. 
 

in other news I had a very strong stench of petrol while driving. Hood down of course. I found the rear carb dripping from the main jet. I also found the choke return spring was not attached. Reattached it and the drip stopped. I expect the jet gland isn’t up to much anyway. 

[Roly]

Reservoir replaced this morning. The old one was corroded at its base. 
 

I also replaced the carb jet glands with vitol o rings. That should get rid of the stench of fuel. 

[Smithfire67]

On 9/4/2023 at 12:04 PM, Roly said:

Having inspected wheel cylinders, pipes and clutch slave cylinder and master cylinders, all is dry. The reservoir is dirty so I shall monitor. All is back together. Now at pub. 

Sorry to jack the subject of the thread Roly but noticed you're running wire wheels.....what thickness tyes are you using?

Clive

[Ian Vincent]

On 9/9/2023 at 12:30 PM, Roly said:

Reservoir replaced this morning. The old one was corroded at its base. 
 

I also replaced the carb jet glands with vitol o rings. That should get rid of the stench of fuel. 

My replacement reservoir started to leak after a couple of years. The unions in the base were sealed with rubber o rings that had turned to jelly. I unscrewed them and sealed them with a suitable oil and petrol proof sealant and since then they stayed fluid tight. 

Rgds Ian