I'm at my wits end- Master Cylinder issues..

Just re-read the whole thread.

I was finally able to successfully install a rebuilt Cardone part (includes front and rear of MC). During the whole ordeal I had ordered just the front assembly from Raybestos which happened to included an instruction sheet that stated the part must be bench bleed or you'll ruin it if you attempt to bleed it installed. The instructions from raybestos also mention when bench bleeding and depressing the cylinder to wait 15 seconds between strokes to prevent aeration of the brake fluid. Slow and steady definitely wins this race

Wish Cardone would've have included that bit of info with their rebuilt units which would probably have solved this issue the first time around.

 

I got my brakes working as good as I have ever gotten them. However even now they don’t feel as good as I would like, but I think it’s as good as it’s gonna get. I’m gonna write my saga, hopefully it will help someone.

chapter 1. The caliper, the drums

I never even thought about my brakes until I had a front caliper stick on me. No big deal I got a new caliper and rotor set and put them on. Put a 2x4 under the pedal and bleed everything. Even that top bleeder on the unicorn piece (FYI I read you have to have the truck running to do that one) no matter how many times I bleed the brakes it was still mushy (did it by the book including the proportioning valve)
I opened up my drums to inspect and found that they were really loose. The automatic adjusters were not spinning the star. So I manually adjusted them till they started to catch while spinning the back wheels off the ground. Bam, much better brakes. And my parking brake will hold on even the steepest hill. This is now my routine. Every few thousand miles I lift the rear and manually click the star a couple times. Only takes a few minutes. This is the first thing I would do if you think you have a brake problem.

chapter 2. New master cylinder, the leak

even after adjusting the rears the brakes still didn’t feel great and I found myself doing the double pump. So I bought a new master cylinder off rock auto (made sure it was a new one not a remanufactured) and once again bleed everything. Still felt the same. Went down a gravel road and mashed the brakes to get the abs moving some fluid. Then bleed again. Maybe felt a little better? Not sure. Then I drove it for a while and noticed my brake fluid kept going down. After the third time filling the reservoir I knew I had a problem. Looked everywhere for the leak and finally came to the conclusion that I was probably leaking fluid into the booster. Not good.

chapter 3. The unicorn.

if you have read this thread you know all about the stupid unicorn. I couldn’t get this piece. Another member (edpix) was able to get a new one from cardone (11-3300) I believe it was. I looked all over and it was sold out. Finally got ahold of someone on the phone at cardone who knew what they were talking about. After explaining what was going on he said oh ya I know that part. We don’t sell that anymore. But WE DO REBUILD THAT UNICORN PART. He couldn’t give me a price but he said just go to autozone and they do the pricing. They send it to us and once we have the part it’s a 5 day turn around. But he confirmed they would rebuild that middle master cylinder part. I almost went this route but figured my truck would be down 2 weeks if you factor in shipping.

chapter 4. Pictures can be deceiving

I found on TRDshop.com our master cylinder for $345. Part number 47207-0C010. The picture shows the entire master cylinder. Bought it figuring new parts would be good. Wrong. Only came with the front part of the master cylinder. Had to return it. But they were easy to work with.

chapter 5. Oldie but a Goldie. Power bleeder

I was frustrated and took a look on Craigslist. 06 tundra being parted out. Complete brake/ booster assembly for $80. Why not, so I picked it up. When I took off my old assembly, sure enough my booster was HALF FULL of brake fluid. Real bad. Coulda sucked it into the engine. I bolted up the new assembly and tried out my dads new power bleeder. I WILL NEVER BLEED BRAKES WITHOUT THIS AGAIN!! First of all so much easier. You chain the seal to the top of the booster and pressurize it. Now instead of “pump” open bleeder, close bleeder “release”. You just open the bleeder, and then have your helper pump the brakes a couple times. Then close it. But the biggest thing is that I got SO MUCH JUNK AND AIR out of my proportioning valve. I had already bleed like a gallon of fluid through my system but using the power bleeder and having my dad pump the brakes pushed through so much more gunk and bubbles. After I was done my brakes feel the best they have ever felt. And if I ever need to, now I have an extra master cylinder to send to cardone to be rebuilt. I think a lot better than $12-1300 for a new assembly from Toyota. I still wish they were a little more firm but I think this is just as good as it will get.

The End

 

All,

It's 03-12-2022. I have had agonies trying to locate the OEM booster / master / "unicorn" (aka "third chamber") assembly. Ordered it from the Toyota dealer in Durango, CO and they sent the wrong part, didn't even RESEMBLE what's in my truck. Tried the dealer where I bought the truck in Salt Lake City, they gave me the correct P/N (I hope), 47200-0C073. They also said that this assembly is on back-order for 100 or so customers, availability date unknown. By chance, I stumbled onto the correct (?) part on Amazon. They showed 2 in stock at a Toyota dealer in Daytona, FL. I immediately ordered it (for a thousand bucks). That was 3/3/2022. As of today, the part hasn't showed up yet, and the Amazon tracking info has now been "updated" to show a new delivery date of 3/18. We will see if it really shows up by then. If not, I'm at "wit's end" too, and my truck is dead in the water, undrivable.

It appears to me that many Gen 1 owners around the country must be having this same issue of squishy pedal and mysterious, disappearing brake fluid. I'm guessing there is something of a "run" on this part, and warehouse stock all over the country is depleted. Not sure if the manufacturer (whoever that is) is planning to do another production run, or what. Very frustrating! Is anyone else having this same problem? Please let me know, and whether or not you are having any luck getting one of these things! I'm not too eager to go the junkyard route on a part this critical, but the options appear to be running out.

Cheers to all!

 

For
Norcalyotaman

Glad to hear you made some tangible progress on your project. Agreed, a power bleeder is a huge help. I've used a home-made version over the years. I just bought a nice one from a place in Vancouver, BC and am very pleased with it. Too bad I can't work on the truck for lack of a new master cyl!

You mentioned that your pedal is better than it has been, but still not as firm as you would prefer. One possibility: air in the ABS module. I've done a fair amount of reading on this topic recently, and it looks like a bidirectional OBD2 scanner with abs bleeding capability is the slick way to go for bleeding the module. You plug it into the OBD2 port, select "Bleed ABS" from the menu options, then follow the prompts for which wheel to bleed, how many times to press the pedal, etc. etc. --- pretty much a "cookbook" situation that apparently gives very good results. The software actually cycles the ABS pump and inlet / outlet valves during this process, and successfully gets the air out of the unit. Only downside: such scanners are a bit pricey - I am looking at an Autel MaxiCom MK808 that will do the job nicely, and it's around $500. I may or may not go that route, but it sounds like the slick way to get ALL air out of your system.

Good luck!

 

Second possibility, FGTs have a soft brake pedal and have had underperforming brakes since day one. The EBC and slotted rotors add more drag and bite which helps, but puts a ton of dust out. Trade off I guess. I live with mine dialed in as far as I can, performance is good, not great. Pedal feel is good, not great. They do not feel dangerous and seem fine under most conditions. Heavy Towing is where the deficiency really rears it’s ugly head.

 

for Knabores ---

Just noticed "Arkansas" in your member info. Where in Arkansas? I ask because I'm an AR native (Little Rock) and moved West (Utah) in 1979. We now live in Colorado, near the four-corners area. We moved back to AR (Fayetteville area) about 10 years ago, but only stayed 3 yrs. and then moved back to UT. We like it in the West, probably will never return to AR, but there are some good memories from our years there.

Cheers ---

 

Cabot, just past the Air Force base near Little Rock. Daughter goes to U of A, son goes to A-State.

 

Spent 3 years @ LRAFB! 80-83 always enjoyed Arkansas!

 

Was born at and grew up next to Barksdale AFB in Bossier City, LA. Thank you for your service sir!

 

Hey guys, I have been reading and reviewing this thread all weekend. I decided remove the brake master cylinder from the booster and I noticed that the fluid is leaking into the booster so I am essentially in the same boat as you guys. Sad thing is that all the Toyota dealers that I have called stated that the master cylinder is on a nation wide back order. I even tried to order the complete assembly that someone mentioned in the previous thread from McGeorge Toyota. That too is on back order. I am lost on what to do. I am a litter nervous on sending my MC in to repair for multiple reasons. I am scared of my MC getting lost in transit.

I decided to do some google searching and came across a website, 50statesautoparts.com located out of FL. They said that they have my MC after multiple verifications and photo verifications but I am still hesitant because it feels like it is too good to be true. Anyone else heard of this website? Besides this website has anyone else found a workaround or different website that is carrying this part? Any help is appreciative.

 

What's involved in rebuilding the master cylinder? New O rings? Baffles? Bore and piston honing? If it's as simple as new seals, then could it be user rebuilt?

 

That's a good question. I don't know. Is there a rebuild kit for this? I am just reluctant to send my ONLY MC to a place unknown to have them rebuild it. If it gets lost in the mail, I am screwed.

 

Has anyone had theirs apart to inspect for worn or damaged seals? There are some of those gaskets and seals available for cheap on Toyota parts sites. I doubt the whole assembly is shot. Probably just one dumb O ring.

 

So Toyota reportedly sells master cylinder rebuild kits. I confirmed the part # fit my truck on two different website and when it arrived, it was clear that the parts were no where close to the same. I ended up determining that the kit was for a V6 first gen which apparently has a different MC. I mailed the kit to Noah last year. I never could find the right part # for my V8.

@titankeeper84 If I were you, I would just order a new booster, paper gasket, and master cylinder from Rock Auto and install it yourself. Since you MC has been leaking into your booster I would assume that's not good.

 

Rock Auto doesnt have the MC in stock. I would have to send it in to get rebuilt. Booster still works and I will replace if needed. I am more concerned on the MC, they are hard to come by. Just to reiterate on what I need, I am attaching the photo of the mc. The outer portion of the mc can be found and purchased, I am still unable to find the middle "unicorn" peace that bolts to the booster. For some reason, no one sells them.

 

@Roman works for Toyota and might be able to help if you send him your VIN. Tagging him in case he knows that part #.

 

Gents,

Wow, the ongoing saga of the master cylinder! I "bought" the full-up master / unicorn / booster assembly off of Amazon 2 weeks ago, for $1K. The tracking info shows it "shipped" and "in transit". When I finally reached the seller (Daytona Toyota) this morning, I was informed that the assembly didn't REALLY ship at all (even though they claimed to have 2 of them "in stock"), it's on back-order with unknown ETA. Bummer, not to mention PISSER! I've spoken to a couple of other stealerships, and the story is the same: back order, no quoted ETA.

I spoke to a tech rep at Cardone earlier. He told me that Cardone no longer rebuilds master cylinders. Maybe that's a recent thing, because it sounds like some of the folks on this thread have been able to get their cores rebuilt by Cardone, with decent results. Or maybe I just talked to the wrong guy - maybe they really do still rebuild them. Does anyone here know for sure?

I just spoke to Toyota Parts Center in Olathe, KS. They show what appears to be the unicorn / MC assembly that Titankeeper84 posted a pic of, but when the salesman sent me a photo of the actual part, it was only the MC, but not the unicorn. Price was $385. I'm going to continue pursuing it with them, the guy I spoke to was nice & helpful and seemed knowledgeable. We'll see where it leads.

Folks above mentioned the possibility of user rebuilds. Good luck getting the piece-parts or rebuild kits you need, but if you do, please let us know. And yep, you're probably right, that one stupid O-ring is probably the culprit. Finding the exactly right O-ring, correct material, correct ID, and correct OD may be a challenge.

Please let us all know if you make any progress.

 

Not too personal but might want to remove VIN # if you have ever registered vehicle at Toyota Owners or done service at a Toyota dealer.

 

Thanks @DsrtRat its nice to know that I am not alone. I currently have my mechanic hunting one down or at the very least looking at ways to rebuild it. This is a huge disappointment for me. My Tundra only has 85k miles on it. Its a great truck but I dont want to send my mc anywhere because if it doesn't come back, I no longer have a working truck. Like I said in my previous thread I contacted 50statesautoparts.com and they claim they found one from a junk yard that they are sending me. Its costing me 518$. I have confirmed via images on the mc I need. We will see if it is a scammer or not. I will keep you guys informed.

One guy i spoke with on the phone from an auto parts store mentioned that I should talk to a Toyota mechanic to possibly converting the brake mc...?? is that possible? @Roman

 

Hopefully @Roman can confirm @titankeeper84

 

Here's a better image to go by as far as what Toyota sells.



The box marked 47201 (big box on the left) is available separately, but no one needs just that part. Everyone usually needs the other half that goes into the booster. You can see in the image there is no number directly attached to it, so you can not get that part by itself. It only comes with everything in the 47210L box (basically everything in the picture). Hope that helps some.

 

Here's the diagram for vehicles with VSC, just in case.

 

Hey again,

Yep, the offending piece is the one between the master cyl. and the booster, and it has a bleed nipple sticking out the top. Some folks on this thread are calling it the "Unicorn" part, which seems pretty appropriate - it seems about as easy to get as a real unicorn. In the Toyota Service Manual, it is referred to as the "third chamber". And it certainly appears that you are right - the only way to get the "Unicorn" from Toyota is to buy the complete assembly of booster, "Unicorn", and master. The part no. for that assy. is 47200-0C073 (that's for trucks WITHOUT Vehicle Stability Control). Depending on where you look, the cost is around $1K or more. And, unfortunately, that's the P/N that's on B/O all over the country, with no statement of when (or if) they will become available. As I've whimpered about above, I located that assy. on Amazon, with the sucker-bait "Only 2 left in stock, order now!!" As I learned the hard way, there were actually ZERO in stock. I can get my $1,003 back, but it's EXTREMELY irritating to be deliberately misled about the situation. Complete with tracking info on Amazon that shows "picked up by the carrier", "arrived at carrier facility", and "in transit". BS!!!

Roman - I noticed "Toyota Parts Master" in your profile. Do you have any insight on the availability of rebuild kits for the master and / or "Unicorn". Apparently Cardone has rebuilt these units in the past, whether they still do or not. That implies that the required pistons, seals, O-rings, circlips, etc. must be or have been available. Any ideas?

Cheers!

 

I personally have never seen where people are rebuilding these, though I have heard of it being done. Until recently, we didn't really have an issue getting the parts, so it wasn't a concern. Now, more and more parts are being back ordered with no telling how long the ETA is. Our back order report is typically 4 or 5 pages long, where this morning it was 17 pages long.

I wish I could be of more help on the rebuild parts, but all that we can get is what is listed in those diagrams. I am sure the manufacturer has/had those parts of course, but we are not privy to nor have access to those parts.

 

Well, gee --- you can only do what you can do. Thanks for the info and the perspective. Those of us who have undriveable trucks are at the point of grasping at straws at this point. It's VERY frustrating to look at a pretty nice truck and (in my case) camper, and be unable to use it with camping season on top of us.

Is there any avenue for applying pressure to Toyota's parts organization to get the back orders expedited? Not that we have any huge bargaining power, with our bunch of 15 - 20 year-old trucks. Small potatoes for them, I'm sure, not to mention a liability issue on critical brake parts.

Mac (aka "DsrtRat")

 

Except oxygen sensors and fuel filter recently ordered I hope

 

It's been a long ass time since I've read through this thread but what's the reason you can't just slap a basic MC off an early 1st gen and disable VSC and/or ABS while you wait for the proper part to become available?

 

Not that I'm aware of. I'm sure Toyota is getting calls daily regarding parts availability. Especially from customers with vehicles at body shops. I have heard from our body shop that some vehicles are going to be waiting months for parts to arrive, and the customer is stuck in a rental until then. Some insurance companies have cut off their rental reimbursement at 30 days, leaving the customer stuck in a rental, paying daily rates, for who knows how long. Some parts are just hard to get right now.

 

I can't find the thread, but Geoffrey Beers on facebook (the guy who does the 14WA brake upgrade) bypassed that unicorn part. https://www.agilitycustoms.com/about-us/

Another option that's expensive, but around the same price as that stupid unicorn part is the sequoia rear disc brake conversion and the sequoia master cylinder.

https://sosperformance.com/t/rear-disc-brake-conversion-tu6

@des2mtn do you have pics of the Sequoia master you replaced?

 

https://www.tundras.com/threads/00-drums-to-discs-rear.101914/#post-2612912

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