My '88 convertible has just over 43,000 miles on it,...There is nothing wrong with my brake master cylinder, but the reservoir seals have begun to 'weep' slightly.
Is there a way to replace those seals? If not, can they be replaced in a master cylinder rebuild? And can one be found?
I believe that my master cylinder is of the '89, and later, type,...
Thanks, in advance!

 

I would recommend just replacing the master cylinder itself. You can order them with and without the reservoir. This is a common thing to have happen. I just noticed that the seals where the reservoir meets the master cylinder in my 10th Anniversary RX-7 are starting to weep.

 

the seals are 0305-49-686B

 

I've heard that most everyone replaces the master. I'd prefer not to (due to the low-mileage), but I AM NOT STUPID when it comes to these kind of choices on old cars (I have collected a number of them, this being one that my father bought new). I am perfectly willing to upgrade some parts of the car, ESPECIALLY if they appear original,...
I'm sorry that I have NO IDEA of where to find parts for my Mazda, other than calling the dealer (it's never needed any, in all of this time!),...First, can j9fd3s, or someone, provide a link for a source for the seals, and secondly, a source for a really good replacement brake master? I would appreciate it more than you can imagine! As would my RX-7!
Thank you very much! Todd.

 

https://www.tascaparts.com/oem-parts...int-030549686b

 

I've never heard of tascaparts but I'm willing to give them a try based on your recommendation. I don't have the same relationship with my somewhat local Mazda dealer's parts department any longer so its hard to get parts locally at a reasonable price. Depending on their shipping, I think they are worth looking into. Other online parts wholesalers charge an arm and a leg for shipping and it more than negates any discount.

 

Tasca is just a dealership, but they do pretty well.

 

Thanks, man! Ordered. Hope these fit my master cylinder,...
The website is hard to search,...looks like it's best to search using the proper part number.
Again, thanks.
I'll follow up,...

 

I've been ordering from Tasca auto parts for years. They're located on the east coast in Cranston, RI. They've got very competitive prices, but as of lately their service sucks. Took me 3 months to get some common Mada parts. BTW, Bob Tasca owns his own racing team (https://www.tascaracing.com/) and I believe took 1st place this year in his Ford powered alcohol funny car.

 

if you try to buy something that needs to come from Japan, the delays are real. in the before time it was 6-8 weeks, and now its like 6-8 months

 

You can still order them straight from Mazda as well which is what I did because of the impossibility of finding a rhd specific one.

 

ya i ordered direct from mazda with this number and had them very quickly and really cheap too(few months ago).

1 screw from memory holding the revivor on. takes a bit of force to wedge off.

 

Received my new seals early last week,...so it took about three weeks. Tasca stated that they were "backordered" when I placed my order, so I really expected that it might take longer,...
They appear to be the correct seals, 0305-49-686B "Bush, Elbow",...but I don't have warm enough temps to attempt replacement right now (but with this weather, it could happen!). I'll follow up, once I've got them in.
Thanks, all!! Happy Holidays!

 

Ya there not too bad fit. Dont take off the whole master from the car like i did . no need.
i should jsut have wiggled the reservoir more. 1 screw underneath from memory.

My master is fecked now so ive to swap that out some day now . annoying

 

The weather co-operated, today, so I was able to do a close inspection of the master cylinder unit and I compared the appearance of the new seals with what little I can see of the old ones,...first impression: the lip of the old seals, just under the reservoir, appears to be thinner than the new seals.
And I find that my master has elements of the older ('86 - '88), AND the newer ('89 -) master cylinders,...Mine has no screw, and a rectangular reservoir - but my cap parts and sensor position appear (enters from the inboard side) as in the newer master. And there is NO brake fluid pressure switch!
STRANGE,...So I have identified it incorrectly,...it MUST be of the 1986 - 1988 master cylinder type, and NOT of the newer type that replaced it in 1989.
I have not discovered how to search Tasca for a part number,...would j9fd3s by any chance have that for brake reservoir seals for the '86 - '88 master cylinder? Or clue me in on how to successfully search Tasca). And while I'm at it,...can anyone recommend a source for a replacement master, if I need to go that route?
Should I just call Subaru (who handles Mazda around here) about the seals? Would that be faster than Tasca? Thank you all very much!
And, I'm gonna end up with an extra pair, one way, or the other, SO,...if anyone needs them, I'd be happy to send them off, free - I'll have no use for them. I'll post later, when I have the PROPER seals in (or a new master, whichever,...).
Thanks again, and please pardon my confusion,...but check out the diagrams! I gotta weird master cylinder in all-factory-original car,...
Happy holidays! All have a good one,...

 

The part number for the seals between the reservoir and the master cylinder should be : 0305-49-686B

A quick check shows that they are still available new from Mazda.

 

The new seals that I received are 0305- 49-686B, but I'm not sure they match the originals (see previous post).
Is that to say that the seals are the same in both the '86 - '88 master, and in the '88 and later master cylinders? They appear similar, but not the same, in the diagram that I have,...I'd prefer to not tear this apart without having what I think are the proper seals. Thanks!
Merry Christmas, all!

 

all of the master cylinders use the same seals, and for a convertible they used the same master for all of them. the factory part has a circle with 3 pips on it, for the manufactures logo

 

I replaced my brake master, and I bought it through Atkins. Along with a rebuild kit, it was easier to replace IMO.

 

Cool, guys! Thanks!
If the reservoir seals are all the same, then I'm in Fat City,...! I'll try to replace them when the weather is warm (in the spring), and hope that I don't break the 33 year-old plastic reservoir.
Now, I'll just need to figure out how to coat my bare left framerail "in situ", since the oozing brake fluid stripped it clean,...! I plan to use a 'rust stabilizer' liquid, such as Permatex.
You guys are absolutely invaluable! Thank you so very much - you're helping me keep this old machine running like it did on day one,...
Update to come, when the weather is warm,...

 

Got 'em in, without too much difficulty.
Reservoir is difficult to pull up, but it will come - careful! Seals are quite hard to get out, and required some prying,...just as tough to get in, but a plastic 'spatula' helped get the leading edges started, then the seals slid in.
BUT, I cannot get the reservoir to seat! Insert, yes,...seat, nope! Any ideas/suggestions to get this re-installed?
Otherwise, a vendor recommendation for a new master w/ reservoir,...perhaps a link? 1988 RX-7 13B conv. with correct master,...
Thank you all very much!

 

Spent the day today struggling with the reservoir. I used a pair of bar-clamps, front and rear (with wooden blocks, to spread the force over the top of the plastic reservoir), and 'mashed' the reservoir down, flush with the top of the seals (as before). The reservoir came back up, to be about 1/4" proud, as soon as I took off the clamps. This is ridiculous,...I quit. It is taking too much time.
I'll start a new thread to see if anyone will respond with a suggested source for a master cylinder replacement.
Thanks for looking, anyway.