1983 340 Brake master cylinder

[940Graeme]

hi all, I seem to have sprung a leak from the brake master/resovoir on my 1983 340. Not fully investigated yet, (only happened today) but I am loosing brake fluid at an alarming rate. The clouds of acrid smoke burning off the exhaust down pipe indicate that it is from the master rather than anywhere else.... On first look, all the unions to the master seem to be tight and without rust etc etc, so my concern is the joint between the resovoir and the master.....is this a common problem? The "Res" does seem to be loose - (should there be any movement? - I have lots, it is positively wobbly ) - and the servo is splattered with brake fluid so it seems there is a leak under pressure (only) from the top of the system. My theory is that, as my car has only 37,700 miles from new, and has been stood for a while, the seals have dried out and so now it is back in regular use at least one has 'blown'. Ideas please, I am minded to get a service pack and replace all the master cylinder seals - good idea? and where do I get one from?? Although this is my 12th Volvo, it is my first 340, so your expertise gratefully recieved!

Thanks in advance
Graeme

[Clan]

firstly bear in mind that brake fluid is highly flamable !!

The rubbers connecting the reservoir to the master cylinder rarely leak , but possible of course , mine are original on my 1980 343 and still fine . you need to determine the exact source of the leak . it could be the reservoir itself or one of those two seals , It might be a good idea whilst you have this problem to fit a complete new master cylinder and reservoir as it is unlikely that you will get the seals now ..... yes the reservoir will move around when you wobble it due to the rubber seals .
These rubbers were very expensive when they were available from volvo .

http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=150383856446

[940Graeme]

Many thanks for this, yes I did wonder about replacing the lot - thanks for the e-bay link, seems cheap for a new master.
Thanks again
Graeme

[Clan]

ask the seller if it comes with the 2 reservoir seals first if you go for it ...

[macplaxton]

Hi, That's dear for a master cylinder.

A friend and I have had one each on eBay for a tenner delivered. Keep 'em peeled...

Lucas/TRW PMB103

Here's one a tad cheap than the last:

http://cgi.ebay.co.uk/200480950764

cylinder repair kit. http://cgi.ebay.co.uk/200481849024 (use only if the bore is pristine).

[Chris_C]

MP, the ebay tenner master cylinders I've had nothing but trouble with, I went through one every 12 months for a few years.

I get all my brake stuff from Kimbers Friction down here in Soton now, they are awesome quality and everybit is refreshed. Think I paid about 30 quid.

[macplaxton]

I'll let you know Chris how long it lasts. Mine was in a Bendix box and Bob's was a Lucas one.

The rest of the stuff I got from Brakes International in Rochdale.

[Clan]

you will also need 2 blanking plugs to blank off the two unused brake pipe ports if your original cylinder has only two outlets ...

[940Graeme]

Blimey! thanks for all the info guys! The repair kit looks good value.....but I guess why not just replace the lot while I am at it? The labour required about the same I guess? thanks for the warning on cheapo cylinders thou....I suppose u do get what u pay for...eh? Anyway, onto it this week......I'll let you know!

Thanks again
Graeme

[TonyS9]

Many years ago my 360 suddenly developed brake failure (around 80% failure). The cause was the rubbers, one had 'flowed' round and blocked the inlet from the reservoir. It was only about 10 years old then. I often thought that it might be an assembly fault and the reservoir had not been properly settled and trapped the rubbers badly.