Master Brake Cylinders
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Master Brake Cylinders
I have removed my rudder pedals and master brake cylinders with the need to do some re-work on the pedal pivot pin holes that are elongated and also to see what can be done with the MBC that seem to leak constantly (the right one more that the left) The part number that is visible on a paper decal on the MBC is 0541138-838. I cannot find any info on the -838 as to overhaul parts and seals etc. As the decal is somewhat faded it is possible that this is not a correct number but under a bright light it does seem to suggest that it is a -838.
Anyone with any info on this one.
Thanks,
Mike
Anyone with any info on this one.
Thanks,
Mike
Re: Master Brake Cylinders
Mike, You'll find some good advice on repairing your rudder pedals here. Especially note sfarringer's repair. Here I noted that Air Repair has new pedals available for $79. Generally, master cylinders are rebuildable. Yours are the wrong p/n but without the drawings it's hard to know if it's a minor difference such as the finish or a major difference such as the stroke or attachment hole diameter. You'll find the correct p/n's in this discussion. You'll also find a lot of moderately priced master cylinders on online auction sites but it may be a challenge getting the correct p/n.
Gary
Re: Master Brake Cylinders
Hi Gary, thanks for the response. I did see the repair thread for the pedals and will do something similar with mine. I have scoured the internet to try and find part numbers for my cylinders so as to order up the seals but have had no luck. The search will continue and as it is now getting down to the minus temps here in Canada no real rush to complete the project. Cheers, miken2582d wrote:Mike, You'll find some good advice on repairing your rudder pedals here. Especially note sfarringer's repair. Here I noted that Air Repair has new pedals available for $79. Generally, master cylinders are rebuildable. Yours are the wrong p/n but without the drawings it's hard to know if it's a minor difference such as the finish or a major difference such as the stroke or attachment hole diameter. You'll find the correct p/n's in this discussion. You'll also find a lot of moderately priced master cylinders on online auction sites but it may be a challenge getting the correct p/n.
Re: Master Brake Cylinders
Seal Kit
Stay warm up there!
... also to see what can be done with the MBC that seem to leak constantly... .
Maybe there's a connection. Remember January 28, 1986? Stay away from Viton o-rings on your MBC rebuild....it is now getting down to the minus temps here in Canada ... .
Stay warm up there!
Gary
Re: Master Brake Cylinders
I recall that day very clearly. Doubt if a failure on my seals on a MBC would have the same consequences however.n2582d wrote:Seal Kit... also to see what can be done with the MBC that seem to leak constantly... .Maybe there's a connection. Remember January 28, 1986? Stay away from Viton o-rings on your MBC rebuild....it is now getting down to the minus temps here in Canada ... .
Stay warm up there!
Re: Master Brake Cylinders
Mike, I link I sent for the o-rings from Sky Geek is a McFarlane Aviation p/n who gets their seal kit from Trimcraft. It might be worth calling them for their price on the kit. But really the only o-rings you need to rebuild your master cylinders are two Lock-O-Seals, p/n 800-001-6, (formerly p/n 200 AC-6) and two piston o-rings, p/n MS28775-110, (formerly p/n AN6227-8). For US $15.46 you can get them from Univair. They're available cheaper elsewhere at places like Yingling Aviation but they have a minimum quantity purchase requirement. Anyway, good luck on the rebuild.
Gary
Re: Master Brake Cylinders
I was just looking at McFarland regarding the brake and master cylinder seal kit. The eligibility list shows the 170B but not the A model. Is there a difference between the brake master cylinders on the B vs A?
Stephen Reeves
Palm Harbor, Florida
Cessna 170A, N1773D, S/N 20216
Palm Harbor, Florida
Cessna 170A, N1773D, S/N 20216
- Bruce Fenstermacher
- Posts: 10320
- Joined: Tue Apr 23, 2002 11:24 am
Re: Master Brake Cylinders
Starting with the B model 20267 to 24999 was a different master cylinder. After 24999 was a different part number but I think the basic cylinder and parts the same. This cylinder has a parking brake lever that is also pulled up the shaft to jam the plunger in place when engaged. It is the most susceptible to being accidentally engaged by the fire wall. This master cylinder has a Lock-o-Seal # 200AC-6, an AN6227-8 and that is it.
Lock-O-Seals have other names like Stat-O-Seal. There is also a MS and NAS equivalent.
When searching for Lock-o-Seal 200AC-6, 800-001-6 comes up most often.
Most of the 800-001-6 seals I found where in the $6.50 range.
If you search Aircraft Spruce for 800-001-6 or Lock-o-seal 200AC-6 you get STAT-O-SEAL NAS1523-8B for $2.45
You will need an AN6227-8 or MS28775-110 as well for the B model for about 50 cents.
(MacFarlene sells the kit CBS-KT-1 for $9.68 which I presume has both)
If you have the early A model master cylinder you are only looking for an AN6227-7 or MS28775-12 for less that 50 cents.
BTW it seems the seals are changing depending on what you get it might not match what you had. Lock-o-seals traditionally where a washer with an o-ring sort of crimped inside. The Stat-o-Seal and NAS pictures I saw look the same. The MS 800-001-6 is two parts. A washer and an o-ring that fits inside.
Pictures from Parker's site. And one last important thing. Many early 170s had their master cylinders changed out to later B model versions OR other master cylinders from Cleveland and Scott. You need to identify what you have.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Re: Master Brake Cylinders
Thanks Bruce. My 170A is serial number 20216. That makes it one of the last "A"s made. So I guess it should have the old master cylinder, but it doesn't. It must have been changed out (not in logs) to the "B" model type as that is what I have. So I'll try McFarland for the kit. Thanks for the info.
Stephen Reeves
Palm Harbor, Florida
Cessna 170A, N1773D, S/N 20216
Palm Harbor, Florida
Cessna 170A, N1773D, S/N 20216
Re: Master Brake Cylinders
Like Aryara, I took apart my master cylinder. I had removed it only for access to replace a skin. At first I thought I'd skip taking it apart but thinking that it too might be full of crud I investigated. And it did have a whack of crud but also it also had a plug from the filling port that had fallen inside. That plug had been there sometime before I bought the plane in 95 .
Now removing the inboard side just to see what's inside
Now removing the inboard side just to see what's inside
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
1953 C170B S/N 25656
02 K1200RS
- MoonlightVFR
- Posts: 624
- Joined: Sun Jan 02, 2005 5:55 pm
Re: Master Brake Cylinders
Just finished both master cylinders C170B sn 26433 1954.
Did not have a McIntosh surprise. Wow, a plug down inside the reservoir!
Spent way,way too much time studying operation of unique brake master cylinder.
Now have great respect for the thoughtful engineering in the combination reservoir/master brake cylinder. There is crud in bottom of these 60 year + cylinders. Very bottom of cylinder allows residue from tiny 0 rings
to accumulate below were the hydraulic fluid is pushed down to brake pucks.Containment. Use Q tips or a tampon to remove residue.
You do not have to remove master brake cylinder to do a complete job.
Did not have a McIntosh surprise. Wow, a plug down inside the reservoir!
Spent way,way too much time studying operation of unique brake master cylinder.
Now have great respect for the thoughtful engineering in the combination reservoir/master brake cylinder. There is crud in bottom of these 60 year + cylinders. Very bottom of cylinder allows residue from tiny 0 rings
to accumulate below were the hydraulic fluid is pushed down to brake pucks.Containment. Use Q tips or a tampon to remove residue.
You do not have to remove master brake cylinder to do a complete job.
gradyb, '54 B N2890C
Re: Master Brake Cylinders
Took the other brake cylinder apart and yep I'm two for two, it's the same type of plug I found in the first cylinder I took apart. Amazing the amount of goo that was also in the bottom, if it's been awhile for your master cylinders, it might be an idea to have a look as it's not a terrible job.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
1953 C170B S/N 25656
02 K1200RS
Re: Master Brake Cylinders
Jim, is there a vent hole through the center of the plugs you found inside your master cylinders?
John E. Barrett
aka. Johneb
Sent from my "Cray Super Computer"
aka. Johneb
Sent from my "Cray Super Computer"
Re: Master Brake Cylinders
No, no holes in them. The other thing I found was the compensating sleeve (item 16) outside diameter surface was rough. I polished the roughness out, maybe it will compensate better now although I have no idea what it's compensating for other than possibly my poor piloting techniques. Then again maybe it won't compensate at all so fair warning to all; don't hang close to the runway if you know I'm coming in
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
1953 C170B S/N 25656
02 K1200RS
Re: Master Brake Cylinders
Source for master brake fluid reservoir filler plugs? Tried checking Spruce but couldn't come up with the correct wording the online search needed.
OLE POKEY
170C
Director:
2012-2018
170C
Director:
2012-2018