Rebuild your Brake MC

[jvb5577]

During my build I read a lot on here about people getting reman. MCs and them not working.  Instead of wasting money I figured I would just rebuild my OE one.  Its a win win!  You get to keep your OE look but have a new MC!

 

 

Tools you will need:

+ Flat head screw driver

+ 17mm wrench

+ 10mm wrench

+ A pick (black handle one in picture)

+ Needle nose pliers

 

 

 

First you will use a 10mm wrench to remove the reservoirs.  There are baskets inside of them to keep contaminants out of the system.

 

 

You will now need the flat head screw driver to remove the ring and washer that holds the internals in.

 

 

Take your 10mm wrench and remove the bleeder nipples and a flat head to remove the screw.

 

 

Take your 17mm wrench and remove the bottom two nuts

 

 

Now you can pull the pistons out of the MC.  First one will have a dense spring

 

The next one will have a spring that widens

 

 

Here is what they look like inside the MC

 

You can see how the rubber is warped and worn.  Not good for keeping a seal!

 

Now you will use your "pick" to brake the seal around the channel as shown

 

Then take your needle nose pliers and remove the rubber guides.  A spring will be attached to them.

 

 

Now you will want to check your walls in your MC for grooves.  If you see any then your MC is junk and you will have to get a new one.  Mine was very clean.  (Hard to see in the picture)  If everything checks out, clean your MC with brake cleaner.  Make sure to remove as much junk as you can.

 

 

Now your ready to rebuild them!   This is the kit I used.  Raybestos MK1093

It contained all of this.

 

 

Prelube your rubbers on your pistons so they slide into the MC easier.  Just use brake fluid but make sure it is clean!  *Remember flared spring goes first*

 

 

Install the guides with springs and follow the instructions on the picture for the guides.  *It matters what one goes where*

 

 

Use your 17mm wrench to tighten back down the bottom nuts.  This will compress everything back down.

 

 

Install the washer and clip back into the front to hold the pistons inside.

 

 

Replace the rubber washer with the new one supplied in the kit.  *this goes on the screw*

 

 

Use your 10mm and flat head screw driver to tighten everything back down

 

 

Install your reservoirs *remember clap goes on then put reservoirs on* and tighten with a 10mm and put in your baskets and your done!

[mklotz70]

Great write up! :)

[Eagle_Adam]

awesome write up!!!!!

[jvb5577]

Thanks guys!  Hopefully it helps someone.

[heretic]

AWESOME write up.!!!

[KlassicMotion]

Great pictures.

 

You really ought to run a hone down the bore a few times though.  This will get rid of most grooves or ridges.  The ridges occur where the seals stop their travel, and three of those locations are too deep to be able to feel with your finger.  You can pick one up at the local parts store.  It plugs right into your electric hand drill.  Use some honing oil with it.  It usually comes with medium grit hones, but fine grit hones can be ordered.

 

[elmerfudpucker]

I motion that this gets pinned, very useful info! :thumbup:  

[SS320]

I motion that this gets pinned, very useful info! :thumbup:  

I would like to second that motion!

Good pics and info. Well done.

[jvb5577]

Great pictures.

 

You really ought to run a hone down the bore a few times though.  This will get rid of most grooves or ridges.  The ridges occur where the seals stop their travel, and three of those locations are too deep to be able to feel with your finger.  You can pick one up at the local parts store.  It plugs right into your electric hand drill.  Use some honing oil with it.  It usually comes with medium grit hones, but fine grit hones can be ordered.

 

My dad actually has one of these. (was wondering what you would use such a small hone for) now I know!  I know what you are talking about deep in the MC.  I used a dull dental pick to check these areas. The MC came out of a low miles truck and was in good working order when removed.

 

I think if your MC is really bad to where you need to hone it, you should just toss it.  Since they don't make larger rebuilds for a hone brake fluid will just squeeze by the rubbers and the walls.  Just my two cents...  This is the first one I rebuilt so we will see.

[jvb5577]

Thanks guys.  Eagle_Adam suggested I do a write up so without his suggestion this would have never been done!

[Eagle_Adam]

i only suggested...

 

 

 

you followed thru!

 

 

 

great info here, and even if its not posted in a lot there will be countless members and non-members that will read this and find it via Google!!! 

[Dawa]

wow i wouldve never thought that wear could occur in the cylinder and to hone it down. interesting. 

 

only thing i would add (even though no one asked me) is to use gloves when handling brake fluid :P

[datzenmike]

I have rebuilt wheel cylinders and lightly polished with fine steel wool. The last MC was the 15/16" from a zx and was spotlessly clean inside. The seals can wear the casting if dirt gets in. Always clean the reservoir caps off before removing to add fluid. 

[Z-train]

Great pictures.

 

You really ought to run a hone down the bore a few times though.  This will get rid of most grooves or ridges.  The ridges occur where the seals stop their travel, and three of those locations are too deep to be able to feel with your finger.  You can pick one up at the local parts store.  It plugs right into your electric hand drill.  Use some honing oil with it.  It usually comes with medium grit hones, but fine grit hones can be ordered.

 

Good info.Taking one step further,after you hone it,take a dentist pick and start feeling all over the bore.If it catches on anything,that is pitting from corrosion and the cylinder is junk-throw it out. The corrosion comes from water in the system. This is why brake systems need to be flushed on a regular basis.

[jvb5577]

Good info.Taking one step further,after you hone it,take a dentist pick and start feeling all over the bore.If it catches on anything,that is pitting from corrosion and the cylinder is junk-throw it out. The corrosion comes from water in the system. This is why brake systems need to be flushed on a regular basis.

Flushing your brake system... who does that?  :P

[datzenmike]

It gets flushed every time you have to replace all the wheel cylinders and the master.

[KlassicMotion]

I was taught the brake fluid should be flushed every year, but I've read that it should be flushed every 30,000 miles, which would equate to every two years.

[Z-train]

I was taught the brake fluid should be flushed every year, but I've read that it should be flushed every 30,000 miles, which would equate to every two years.

Here in the Desert every two might work.In damper enviroments,the period needs to be shorter.

[jvb5577]

How often do you say a MC should be rebuilt?  I am curious to see how long this one lasts. 

[KlassicMotion]

Like anything on a car, they seem to last longer when they don't sit.  A new master cylinder, I'd say it woud last past your ownership.  A rebuilt unit.... Would be anyone's guess. 

[Trophy24]

The brake fluid service interval I have always worked with at the dealership is 2 years/or 30,000 miles.