Replacing Brake Master Cylinder

[drew_ae86]

Hey guys,

My break master cylinder has a steady, slow leak at the firewall and I need to fill up every morning before I drive the car.

I'm worried if I don't fix it immediately the slow leak will become a fast one and I'll be using the handbrake as an E-Brake :|

My clutch fluid is getting low regularly now since the leak started, are they linked?

It's a stock ADM Sprinter- what is the best thing I can do to get this sorted? I'd rather not swap for a second-hand unit because I don't want the issue again in 9 months. Should I have it rebuilt or do I convert to a different BMC that is easy to replace or buy a repair kit for?

If I have it rebuilt, where is the best place? ABS has been suggested and I've been put on to Kent Engineering on Port Rd.

Cheers-
Drew

[ke70dave]

<div class='quotetop'>QUOTE (drew_ae86 @ Jul 24 2008, 12:11 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=565958)</div>
My break master cylinder has a steady, slow leak at the firewall and I need to fill up every morning before I drive the car.[/b]

man that doenst sound slow to me!!!:P

i woudlnt drive it to much like that, one thing you don't want to have is your brakes failing:P (happend to me last week, mmm busted caliper)

now I'm from QLD so can't point to towards specific shops...

but up here there is a place i took my mastercylinder, and got them to re bore it and replace everything with stainless steel

the reason yours is stuffed is prolly cause its rusted innside (brake fluid attracts and holds water), and thus it can't seal properly.

this is the reason i was reluctant to get a brand new one, cause figured it would happen again eventually.

keep in mind the stainless steel option is quite expensive (bout 180$ it cost me) but for the peace of mind i reckon its worth it.

I'm not sure if you can buy brand new ones that are already stainless steel (aftermarket/non genuine companies may make one?) but the place i went to was just an exchange service, and they did all the work therer.

its actually good to hear someone that wants to do the job right! and not just slap on another 2nd hand one!

as for the clutch fluid, they aren't linked (though they use the same fluid), you can buy brand new clutch masters off ebay for about 40$ (i got one a while ago, still sittin in its box waiting to be used...)

not sure about clutch slave, I'm guessing you can buy a new one of these for simliar price (your local repco/bursons etc should have these available)

I'm not as worried about getting these in stainless steel ($$), cause if they fail (very unlikeely) then it doesn't matter as much as the brakes...can still either get home, or get it towed safely.

hope this helps!!

ps: clutch/brake fluid is DEADLY on paint, it will just destroy it and eat it!!! (its not so good on your hands either...)

[drew_ae86]

Thanks for the info.

Got a heap of info ringing around. Lots of bullshit from various repairers/suppliers. $700 from Toyota (ex-repair), someone else was $350 ish new. However, I found a great engineering place that supplies parts and they had BMC new for $110, and CMC for $44.

No idea if the BMC is stainless steel sleeved etc, but not too stressed. If it lasts 5 years or so I'll be happy, car is due for new break setup soon in preparation for an engine conversion, so all of that stuff will most likey change.

I'm going to change the lot myself, all looks fairly straight forward, however I haven't bled the break/clutch lines before and I think the clutch need's some adjusting because it's 6 months old and not engaging very crisply.

Anyone have any links on bleeding the lines just so I know what I'm up for?? Any special tools I need?

[Golberg]

<div class='quotetop'>QUOTE (drew_ae86 @ Jul 24 2008, 02:08 PM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=566006)</div>
Thanks for the info.

Got a heap of info ringing around. Lots of bullshit from various repairers/suppliers. $700 from Toyota (ex-repair), someone else was $350 ish new. However, I found a great engineering place that supplies parts and they had BMC new for $110, and CMC for $44.

No idea if the BMC is stainless steel sleeved etc, but not too stressed. If it lasts 5 years or so I'll be happy, car is due for new break setup soon in preparation for an engine conversion, so all of that stuff will most likey change.

I'm going to change the lot myself, all looks fairly straight forward, however I haven't bled the break/clutch lines before and I think the clutch need's some adjusting because it's 6 months old and not engaging very crisply.

Anyone have any links on bleeding the lines just so I know what I'm up for?? Any special tools I need?[/b]
Well I've got this cool bottle think with a magnet which you stick to the side of the car so that the air runs straight up and out of the system, bought it a repco.

Just buy a rebuild kit for your clutch master and slave, cost me a whopping $20 all up for the both.

Oh and only use DOT3 brake fluid.

[StockAE86]

Replace it with a 1" non abs r32 master, have one in my car, works a treat.

Gives better pedal feel too.

Not sure on cost though, it is from a dirty nissan so can't be too bad

[stefan]

if its leaking on the firewall its the rear seal on your booster!

if it leaks on the front can be either master cylinder or front seal on the booster

if u do rebuild ur master make sure u hone the bore and check for and scores/pitts

or youll just have to get ur master cylinder resleaved @ your closes PBR or brake repalcment place!@

[drew_ae86]

Installed the lot today.

Changing the clutch master is a bit of a prick, the upper internal mounting nut/bolt is really hard to get a ratchet spanner to.

But all done, clutch didnt really need bleeding. Breaks do, but work fine for now.

Both had been leaking, the clutch master at the wall for some time and was beginning to leak inside, and the break master at the booster, pissing out steadily. Glad its done- Thanks for comments

Cheers-

Drew

[Golberg]

<div class='quotetop'>QUOTE (drew_ae86 @ Jul 26 2008, 12:22 AM) <{POST_SNAPBACK}> (index.php?act=findpost&pid=566876)</div>
Installed the lot today.

Changing the clutch master is a bit of a prick, the upper internal mounting nut/bolt is really hard to get a ratchet spanner to.

But all done, clutch didnt really need bleeding. Breaks do, but work fine for now.

Both had been leaking, the clutch master at the wall for some time and was beginning to leak inside, and the break master at the booster, pissing out steadily. Glad its done- Thanks for comments

Cheers-

Drew[/b]
Wait... are you saying you changed the clutch master over and it didn't bleed the system :confused:

[Jonny Rochester]

Sometimes you get lucky, and just by having the beed nipple open you "gravety bleed" the system and it works. Other times you have to pump the pedal and crack the nipple open to get air out. On dirty Nissans (never quite as well designed) they have a bleed nipple up on the clutch master also, which needs to be used.