The International Cessna^® 170 Association

Intent is to rebuild Right Brake Master Cylinder.

After installing new parts I will bleed brake via "bottom Up " method - small pump oil can with clear tubing at right brake cylinder.

I want a small plug with nipple on top to temporarily replace the YELLOW Vent plug while bleeding the system. Clear tubing from top of master cylinder to small glass jar set on cockpit floor observing bubbles.

Problem cannot find plug to fit top of Master Cylinder. Took Yellow plug to Auto Parts Store - cannot locate any plug that fits.

Can anyone help with dia of plug and number /type threads ?

Searched the forum - located one post owner stated catch over flow w rags - I want glass jar - Am I wrong?

Appreciate any advice. It is a 90 mile round trip for me to work on my airplane.t

You need a 1/8" NPT to barbed hose fitting. And some hose to put on the barb so fluid doesn't geyser everywhere.

http://www.homedepot.com/p/Sioux-Chief- ... /202254840

I found mine at Home Depot along with the pressure pot I used.
The pressure pot (small garden sprayer modified to take a hose) made it really easy to flow a lot of fluid thru the system and make sure there were no bubbles.
Bleeding bottom up and into a jar is the right way to do it.

I got my plastic 1/8"npt hose barbs for the master cylinder overflow bottle at the local auto supply for use in auto vacuum systems. We have an old-school auto supply in Fredericksburg. Don't know if you can get them at the franchise stores.

I also just use a dedicated thumb pump oil squirt can with clear tubing over the spout. Circulate the 5606 back into the can until all bubbles are gone then connect to bleed valve and purge the brakes from the bottom up. Rinse out completely with 100LL after use to prevent the 5606 from gumming up the pump.

I am still on the hunt for correct size 1/8 in NPT barb to fit in top of master cylinder. I purchasde the one in the link at home depot. Threaded portion is huge dia 3/8 and coarse threads. Yellow plug is approx 5/16 dia.
Clerks at big box sometimes don't disccern NPT.



Thanks for the direction . I will inquire the auto vacuum systems at parts house.

Here you go, enough for you and all your friends.

http://www.ebay.com/itm/like/2520996920 ... noapp=true

I think my system is similar to Richard's. Instead of a garden sprayer or one of those expensive garden-sprayer-like bleeding units sold by ATS and others, I use a 1 qt thumb pump "oil can." You can get one from Tractor Supply for not much http://www.tractorsupply.com/tsc/produc ... _vc=-10005. I screwed off the flexible metal spout and replaced it with a hose barb fitting, clear plastic tubing and a hose clamp from the hardware store. (The flexible metal spout just gets in the way.) Works great. The thumb pump is very easy to regulate. And the fill cap at the top of the can makes it very easy to re-circulate the fluid back into the can until the clear tubing is free of bubbles. I store the whole thing, along with an aluminum tray for putting under the wheel to catch drips, in a 5 gal bucket. Nice and neat. But I must confess that I just use a rag at the master cylinder end as I always seem to have someone to watch for when the master cylinder is full. The ability to nicely control the rate of flow with the thumb pump minimizes the overflow. I should make up a bleeder jar, hose and fitting like others mention, though.

It's the same system an IA friend of mine has used for eons. I just copied it.

You are making much more out of this nozzle than needs to be. It is not needed to do a clean job. All it does is allow one person to bleed the brakes quickly because they don't have to be careful.

First surround you master cylinder with towels that will absorb any spillage.
Get your helper to look into the ms with a bright light while you pump the fluid from the bottom.
Helper with light stops you from over filling.

I'm assuming you are bleeding just the master cylinder (MC) and the brake line from the wheel cylinder up was not cracked open. This being the case there will be no air in the line. If your wheel cylinder (WC) and brake line has been flushed and empty, pumping from the WC to the MC will also not leave any air in the system.

If you are bleeding the WS and the line has fluid in it crack the line at the WS and bleed the air out there before pushing air into the line. Then bleed the the MC.

If you are working by yourself you need to pump a few pumps then look at the MS level and repeat. Worst case is a little fluid comes out the top and caught by your towels. Using a dip stick as described by Arana would show you how much fluid entered the MC per pump and you can gauge how many pumps you can get away with without over flowing the MC.

If you must have a nipple and can't find one, I'd have taken a plug and drilled it for a tube barb and glued it in to the plug by now. I would then have the additional satisfaction thinking of how skillful I was making the indispensable tool that I now have to track for the next use, but will quickly loose.