54 merc power brake booster

[red carr]

Booster seems to check out ok but when I push the pedal, it obviously loses vacuum to the point that engine almost dies. Have 16 in vacuum at manifold connection. Can find no hose leaks. Looks like a rebuild but want some expert opinions.

[miker98038]

Sounds like an internal problem in the booster to me, creating a large vacuum leak. Does it still seem to be providing boost on the brakes?

Did those use the remote units like my 55 bird, or a treadle vac, or just what?

[red carr]

mike
This is a treadle vac. Get no boost whatsoever and pedal is rock hard as expected without the booster. I know there are kits available and it should not be over my skill range Could it be just a check valve?

[miker98038]

I don’t know. My one and only treadle vac experience was to help a friend remove one and replace it with a modern conventional booster. What I do remember is there was some complicated linkage/bellcrank that operated it. But it was a 56 Chev and you buy any kit for anything for them.

I do know they are rebuildable, I’ve no clue to the level of difficulty.

Kultulz seems to have as many part numbers, etc. as anyone on here. Hopefully he or someone will chime in and help.

[KULTULZ]

Originally Posted by red carr

Booster seems to check out ok but when I push the pedal, it obviously loses vacuum to the point that engine almost dies. Have 16 in vacuum at manifold connection. Can find no hose leaks. Looks like a rebuild but want some expert opinions

If the booster application kills the engine, them you have a massive vacuum leak. You state 16in vacuum. You need a minimum of 18" for one to work properly. How is the state of engine tune? Valves been adjusted lately? What shape are the service brakes in?

You are getting 16" at the check valve? Does the check valve work correctly? Last date system was flushed?

Here is a tutorial - http://ford-mel-engine.com/viewtopic.php?t=149

Feel free to ask anything you need more info on.

[Merc Cruzer]

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Check the vacuum storage tank. They are are mounted under the car, drivers side, and subject to rust and pinholes.

Rebuild kit: https://www.kanter.com/gallery.aspx?...Router=Catalog

Can they be rebuilt? Yes, this is what mine looked like, when I got the car. It has worked perfectly ever since I cleaned it up and rebuilt it. So no mater what yours looks like, don't let it scare you.

KULTULZ: thanks for the tutorial, it will go into my archive, wish I had had it when I was rebuilding mine, 10 years ago.

[red carr]

Ok, think I finally got logged in right.
Miker thks for the comeback. everything helps.

merc cruzer.. thks, never thought about the tank maybe rusting. Chked hoses but not tank.

Kultulz Thks. never thought there would be so much priceless info out there. valves are adj to '018,gauge reads steady at 16 (don't know why so low),timing is right on, service brakes will work but my 89 yr old legs won't push quite that hard anymore, fluid level stays constant. Looks like I better get out the visa card and the tool box

[KULTULZ]

Originally Posted by red carr

... valves are adj to '018, gauge reads steady at 16 (don't know why so low),timing is right on, service brakes will work

Your adjustment may be a little tight. FYB is hard to set if the rocker pads are worn - http://y-blocksforever.com/tech/html/valvelash.html

Something isn't quite right on the vacuum Red. Look at the chart below -

[KULTULZ]

Originally Posted by Merc Cruzer

KULTULZ: thanks for the tutorial, it will go into my archive, wish I had had it when I was rebuilding mine, 10 years ago.

You are quite welcome. Unusual subject as they were mostly GM installed.