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Is this Brake Master Cylinder Salvageable?

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Eric_B

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Hey guys, so i bought my GT6+ partly put together and partly in boxes. (haha, i know.) And my brake master cylinder wasn't hooked up. The lines are ran but the master cylinder was in a box. It looks like it has sat a while and the valve (or plunger, whatever you want to call it) seems to be seized. Is there something i can soak it in to loosen it up? Or just spray some PB Blaster on it? I'd probably rather soak the whole master cylinder in a penetrating liquid so i know the whole thing would get cleaned. Also, once that is done, could i paint it with a black rustoleum type paint? Or do you guys prefer something different? Oh, and here are some pictures of the Master Cylinder.

IMG_0437.jpg


IMG_0433.jpg


Or do i just need to buy a new brake master cylinder?

Thanks guys!
-Eric
 
It's not what's on the outside, but what the cylinder wall looks like on the inside that matters with hydraulic parts.

You'll have to get that apart to really know.

EDIT: Seized is usually not good for these. Remember, your life and the lives of others depend on them.
 
Eric, if it's siezed from rust, the bore is probably pitted. If it's pitted it would not be a good idea to use it. You might be able to hone it smooth or have it relined, by a place like Apple Hydraulics.
I have no experience with Apple, myself, but I bet someone here has.
 
I'm not sure why it is seized. But how do i get it unseized to figure out if i need to replace it or not?
 
If it were mine and it didn't come apart after one day of soaking, it would be in the recycle bin and I'd be on the phone ordering a new one. JMHO.....
 
You could soak it in any penetrant or even brake fluid. Try to break it free first with a wooden dowel and hammer. Compressed air is the easiest way to push them out when they are free.

But listen to the other recommendations.
 
Trash Can It. It's not worth the hassle of a failed overhaul, and brake fluid going everywhere and ruining the paint. Besides, it is not a good idea trying to save money on something as important as the brakes. The bore is going to be pitted anyhow.
 
Well I'm more of an optimist, perhaps because I use DOT 5 brake fluid (which won't ruin paint). Forgot to take pics of the MCs on my TR3, but they looked pretty much like the clutch slave did, and it actually cleaned up pretty well.

In your case, I'd start by squirting some PB Blaster both inside and around the piston, then trying to tap the piston back into the bore with a hammer and suitable drift. The idea being to get it moving, and hopefully loose enough that the spring will pop it out. You can also try some air pressure, if you have compressed air available.

In extreme cases (like the clutch slave), what I do is squirt some carb or brake cleaner (any volatile solvent will do) inside the cylinder, then use bolts, nuts and washers to block off all of the fittings. Then clamp one ear in the vise, with the opening pointed somewhere such that the piston won't do any harm if it flies out, and start heating the body with a propane torch. The heat helps loosen the piston, and the boiling solvent provides the pressure. Keep heating until it comes apart.

Obviously it's best to wear eye protection while doing this; as there may be a small burst of flame when the piston pops out. And the piston will usually fly out with considerable force ... one of my MC pistons is still up in the rafters somewhere.
 
Some people, quite a few in here disagree just because. It is just plain stupid to encourage someone who is not a mechanic, and has little if any mechanical experience, to skimp, or go cheap on brake repairs. It's all fine and dandy to disagree on engine repairs, transmission, etc.. But, when it comes to safety, putting someone else's well being at risk, quite a few people in here are selfish, inconsiderate, ignorant, and just plain stupid. Not to mention not qualified. If someone doesn't care about their own well being, that's fine, but to put other peoples well being at risk, is disguisting. I can see sooner or later someone will get a wake up personal injury lawsuit in here, and you won't be laughing then. And, if you don't like this post, tell Basil.
 
Eric- as a non-mechanic myself, my advice is trash
the old master cylinder and purchase two new ones.

The odds are high one will arrive defective, so you
install the good one and return the defective one.

Or if both are OK - keep the extra for a spare.

regards,

dale
 
It is seized because the piston is rusted to the bore.

It is salvageable & useable, but to be useable it will need to be sleeved by a company like White Post. Sleeving it bores out the inside a bit more & inserts a non-corroding brass sleeve for the piston to travel in.

It should be salvaged if possible, because the next rebuild/repairs will be less expensive, & replacement parts more & more do not look the same, perform as well, &/or last as long.

My advice would be to get a new MC now to put on the car, & start work on dismantling the seized one. Then store the disassembled original so that when the replacement starts to leak & needs a rebuild, you can send the disassembled original off for re-sleeving & just swap it onto the car. Future rebuilds will just require replacement of the seals.

The piston is not likely to have corroded to the point of unuseability. White Post's instructions (from back when they just sleeved the cylinder & didn't rebuild the whole thing) mentioned that if the piston has jagged pits, etc. to just dress them up (smooth the jaggies down) with some fine emery cloth. This is because the piston in operation doesn't contact the cylinder walls; the replaceable rubber seals on the piston are what make contact.

To get a stuck piston out:

Even if it's a good condition MC, the piston is often difficult to remove. Forcing it out with compressed air or forcing in grease via a grease gun doesn't work well with a dual MC because of all the other holes. The method is to use inertia: get a 2x4, drill a hole in it larger than the big hole on the front, put it on the floor or bench (or carefully arrange 2 2x4's slightly further apart than the big hole).

Grasp the MC very firmly with some large, long-handled Channellock-style pliers
Channellock_GripLock_Utility_Tongue_and_Groove_Pliers_GL12_Shop_Tools-resized200.jpg

Then with a long, easy, tennis-style swing, whop it down on the 2x4 arrangement so that the wood stops the flange on either side, but nothing is in front of the hole in front. Inertia will cause the piston to keep traveling forward & out. You may need to do it several times, but it should be the long, even, firm swing. Whapping it with short swings doesn't do much.

As corroded as yours is, you'll likely need to soak it for a long time in penetrating oil, just throw it in a container with Marvel Mystery Oil or something for a week or more. If it still won't come out, you'll need to wash out all the oil (and dry it to inhibit more rust), then heat the MC as hot as possible immediately before swinging & whopping.

It's a procedure you'll need to master & is annoying on the learning curve, but brake hydraulic rebuilds on these cars are sort of regular occurrences. Fortunately they're really easy on cars that have been regularly running, as opposed to your long-sitting up example.

Dismantle the MC, store it (with a film of oil on it to inhibit rust), when the next rebuild time comes, send it off to be re-sleeved. This is one of those OEM parts which hasn't been improved in later available parts. I wish I'd saved all the master & slave cylinders I tossed in the trash during the years of easily-available original BL/Stanpart/Lockheed/Girling parts.
 
Eric
I have to say that I would look at getting a re-sleeved unit from a reputable re-builder.
I agree with Tinster, about buying 2 as the new parts seem to have alot of infant mortality. This to me just adds to the case for buying a re-sleeved unit.
Then when you add in the fact the the re-sleeved units are done in brass, which should greatly reduce or eliminate pitting due to water, if used along with some periodic maintenance to flush the system, should make this a much more reliable and robust system.
My experience has been one failed out of the box new girling unit, and one brand new and currently installed failing unit. This is with about a year of service. SOooo!

I am seriously thinking about ordering re-sleeved units for the TR6 and the Spitfire and including the clutch M/C and slave on the Spit.

Has anyone used Apple Hydraulics for this service? Please PM me.
I have their rebuilt H/D shocks and they are great.
 
I am using a rebuilt mc from Apple on my TR6. Very pleased with it. They bore and sleeve to the original size so rebuild kits will fit later on. The delivery time is very good too. You send the core after you receive the unit.Good price also.
Paul Jones
suzi6
 
I had all my brake and clutch cylinders sleeved with stainless steel by Apple. They did a great job. They sent very specific instructions not to use Dot-5, which I ignored. About two years now with all working great.
 
Alright then.. Looks like i'm going to order a new one then. I'll probably keep the old one though and look into getting it re-sleeved. Thanks a lot guys!

-Eric
 
By all means, Eric, do hold onto the old one. There are a couple factors at play here:

Re(sleeve and re)build: Currently, I believe that no OEM rebuild kits are available for the GT6 master cylinder. There are aftermarket kits available but, judging from the price, I'm assuming they're not as comprehensive as were the original Lucas/Girling kits (I'm thinking that these kits are just seals and don't include a new tipping valve or other little bits that used to get replaced). I've also heard vendors themselves say that the aftermarket kits are NOT as good quality, so....

New: I think you can still find new Lucas (formerly Girling) dual master cylinders...but they're for Spitfires, and there IS a difference. I know some folks have used these in GT6s and didn't have any problems doing so. Unlike the Spitfire, though, the original GT6 dual master cylinder was a stepped-bore cylinder that provided more braking to the front, due to the much heavier six-cylinder engine. How your Toyota engine compares in weight to the six, I don't know, so maybe it's even less of a factor. I also see that companies such as Spitbits do seem to offer a unique part number for a GT6 master cylinder, but I think it might be an aftermarket part. I've not been much of a fan of aftermarket hydraulic brake cylinders on these cars, although they do seem to function.

So there you have it! :smile:
 
Send it to
Apple Hydraulics
1610 Middle Rd.
Calverton, NY 11933

Call them first
800 882 7753
Look at the web site
applehydraulics.com

The prisce is not the ONLY reason, it's the quality.
 
Searcherman,

Concerning your comments about quite a few people being selfish, inconsiderate, ignorant and stupid are very much out of line and uncalled for. Some of the rudist comments I've seen on this Forum have come from you.
There are a lot of people with solid backgrounds and many years of experience with cars who contribute here.
Tact can go a long way. You don't get people to listen to you by insulting them or ticking them off.
Eric asked a good question. Everyone responded lending their advice, none of it bad. He should be able to base his decision taking his level of expertise into consideration.
 
Eric,

Go get yourself a new/rebuilt one,

and then plonk this one in a vat of Evaporust. Pretty amazing stuff. Leave it in there a few days, while you play with the new one, pull this one out of the soup, and have a go with gently getting the piston to move. Sometimes if you can get the piston to move into the bore, a return trip to the evaporust will finish loosening it up.

Air pressure, or the above mentioned aggression therapy method will finish the job.

If you have bowed often enough in the general direction of Coventry, the bore will be smooth and oily, and ready for a kit and a return to the spares collection.

Steve Spangler
71 Spitfire MKIV
Lancaster PA
 
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