Anyone have experience with these?

Noticed my driver was not responding brake-wise as it normally did - pedal felt 'hard' and I needed to really stand on it for it to stop -

I adjusted all four drum shoes for wear

Checked vacuum connections

No hydraulic leaks

Sometimes it feels as if the brakes are 100% what they should be, sometimes they feel like manual brakes.

I'm thinking the treadlevac unit is simply "going", but don't really know - this being by only exposure to one

Considering upgrading the master cylinder / booster, but would like to keep stock appearance (don't want to hang a master on the firewall) - any info on that conversion would be helpful - I seem to remember someone doing it somewhere...maybe not even on this board..

Thoughts, opinions, suggestions, sarcasm are all welcome.

 

There is a thread on here where a guy rebuilt his. Try a search. Fusick's has a rebuilding service where you send it in and they rebuild in and send it back. You might do that when you store the care for the winter

 

I'm more leaning towards replacing with a modern system with stock appearance

 

Gordon

Just curious, did you pull the vacuum line from the tank or carburetor and if you did did you hear a sucking noise of in rushing air?If not your vacuum check valve could be the problem and a lot cheaper than a total rebuild or a conversion.

If you do a conversion I would like to know how it works out. I've thought about this a little and I think it could be achieved by making ( adapting ) a fixture to the removable toe board that would support a small power booster and master cylinder in reverse of normal position,It may need to be extended so all this takes place under the drivers seat this would eliminate the need to change the swing peddle arrangement from the original and any room needed could be cut from the floor under the seat to allow the booster a little more room.The plumbing would all have to be extended and custom built but I think it is all doable... Just a few thoughts....Tedd

 

Tedd – I’m pretty sure that the Treadle Vac is going – every diagnostic guide on every brake website indicates that “hard pedal / feel like you won’t stop” is indicative of a failed power booster – since this is integral with the Treadle Vac, I’m going to assume the same.

Been doing some research – couple of sources for front disc conversions out there – awaiting the answers on some inquires (may need different wheels is one of them) – but I stumbled on a guy who did a conversion in a 56 Packard, which has a very similar system to our Olds, using a Treadle Vac. He used a booster / master from MPB and it fit in the stock position with only a little modification – he added a remote fill reservoir and did some slight mods to the hanging pedal assembly (also similar to ours) and is very happy with the results.

If I do go with this system, I’ll start a thread with it as I’m sure there are a few others out there that will benefit from it.

I’ll keep you posted.

 

Why don't you check probably the most basic thing of your problem? No power assist could mean a simple hole in the bottom of the vacuum canister, crappy check valve, or a hole in the steel line? Don't just inspect it - verify it is indeed holding air. Every one of my tanks rusted out on the bottom - probably condensation forming inside of the tank and it eventually caused pinholes that led to bigger rot holes.

 

There are a few things to try before you get started. As you mentioned, all the diagnostic guides indicate the vacuum booster is not working. However, a vacuum booster will not work without VACUUM. As Tedd mentioned, there could simply be a failure somewhere in the vacuum circuit which is impeding the function of your booster. It could simply be the check valve, or it could be a leak somewhere. A common source of leaks is the vacuum reservoir canister inside the driver's side frame rail. You can put a pump on it to see if it holds vacuum, or just bypass it and see if you have brakes. A buddy of mine just fixed his by bypassing that canister.

I don't blame you for wanting to go to a modern setup, all else aside. However, its a little tough to do with a stock appearance. The pedal in our 55's pushes the master cylinder push rod, where a newer style swinging assembly pulls it. I have seen two different ways of mounting a newer master cylinder in a hidden location... One way, was a guy on the HAMB who put a standard dual master cylinder on a small diameter booster in the stock location on a 55ish Cadillac. To achieve this, he cut the frame section involved out of a donor car, and did all the R&D for the linkage and fit on a bench. After fabricating all the brackets and linkages, he was able to successfully mount it in his vehicle. The second way I have only seen on custom cars, so not sure if it would fit in a stock setup... It would be to mount the master cylinder under the dash. This is a fancy bracket that mounts it all 90 degrees from the standard orientation. If you want a peak at how it works, a member here name JOZW30 has a thread in the non-olds powered forum about his hot rod... Its a 1955 that is getting an LS. Hopefully this helps and I didn't run on too much... Good luck

 

I know this is your daily driver and being able to stop with the everyday traffic is a concern. Seems we can keep up with all the modern cars but I find it hard to stop with them in a panic situation. Disk brakes would be nice. I understand your reluctance to return to something you feel is inadequate and outdated.....Keep us updated on whatever you do.....Tedd

 

Sincerely appreciate all the input - I've seen the '55 build here with the under dash setup (real nice). I also saw that thread on the HAMB (Olds Dad there too) - I happened on a Packard thread where they had a similar setup to the Bendix style Treadle Vac and they did it in the stock location with a MP Brakes hardware and a little modification to the standard pendicular pedal (like mine)

With regards to the canister, mine's been replaced with a pvc tank (which holds vacuum), but I'm unsure of the purpose of this tank anyway - is it for auxilliary vacuum, or just in case of engine failure?

Not sure how to check the 'check valve' either - any suggestions?

I got under the car today and took some measurements - I think a 7" diameter booster with a right outlet, remote fill master would fit - going to contact MP Brakes tomorrow and get some input.

I'll keep y'all posted

 

The vacuum reservoir is so you have brakes in a low vacuum circumstance or as you mentioned during an event of engine failure. The check valve is in the vacuum line in between the base of the carb and the booster itself. It is a little canister maybe an inch or so in diameter. To check it, remove it and if you're not too germiphobic, suck on it from the carb side. It should pull air through. It should not feel impeded or restricted. Now blow in it. It should stop the air from going the other way. If it fails either way, It should be replaced. I replaced mine with a non correct one from the HELP! section at the McParts store. It is made to plug into a newer style booster, so It is more of a 90 degree elbow than a straight through canister, but it will work. Hopefully I didn't leave anything out... Good luck

 

OK - I've been told I both suck and blow at various points in my life, so this is my test!

I do see it there, but I'll deal with it tomorrow...late now - too many IPAs in to get into something now!

 

So, I had an unfortunate conversation with MP Power Brakes - had some questions regarding certain master cylinders configurations, power booster "boost", etc - never once did I say "how to I convert my olds to modern brakes".

In short, the guy (Kevin) was combative and very rude - for a website that promotes themselves as being for 'customs, hotrods, classics', they are not.

I was polite, well spoken, asking intelligent and specific questions. All I got was resistance.

I told him squarely that I did not appreciate him being combative and that I was going to spend my money somewhere else.

 

Took the vacuum line off at the check valve (accompanied by a "Pop" - presumably stored vacuum escaping) - and 'checked' the check valve which seems to be operating properly. Air flows only in, not out.

Couldn't put my hands on a vacuum gage / pump last night, but will try to see if the system is holding vacuum - seems to be though based on the 'pop' I heard.

Funny thing is that last night, I drove it, and 50% of the time the brakes felt great, the rest of the time they were hard as a rock.

Very strange - still think the unit itself if suspect #1

 

The "pop" was a good indication its all working good. The check valve trapped vacuum in the tank, and the tank held it. If for kicks you want to check the tank, you could try to pressurize it a bit I suppose, and see if it holds. However it does seem like it might be narrowing down to the booster itself. Inside of it is a big leather cup maybe 8" in diameter that acts to seal the piston inside of it... Potentially there could a flaw in it but the sporadic nature of the malfunction is pretty curious. They are not too tricky to rebuild if you can follow all 100 steps in the manual... Basically its a lot of steps not too tough. Now its in your court whether to fix it or upgrade. Good luck

 

leaning toward the upgrade - of course, that means upgrading to discs in the front as well - so I'm scrounging around for that extra
$1000 I'll need to do this all - really need to do it - makes all the sense, but I only paid $2000 for the car..I know I know...safety - security...just have to wrap my head around it...trying to restore my 2 door sedan at the same time and not spend money like my name rhymes with TheRock Oglama

 

If you want to make things a little easier for yourself financially, you can start with just the booster upgrade. If you mount a drum/drum dual master cylinder to the new booster, you will be able to keep the drums, which for the most part will still stop pretty good. Then later with a master cylinder swap and a little bit of plumbing you can do the discs when you have the cash. Thats more or less how I'm going to go about it... For all you know you might be satisfied with the results of the booster swap... Just something to consider

 

Gorden, here is half of your fix on this link keep us informed on the hard half.......Tedd

http://motors.shop.ebay.com/Parts-Accessories-/6028/i.html?_nkw=1955+oldsmobile+parts[/URL]

 

Took mine off, checked it out, bought a rebuild kit and new hose, rebuilt the mc and vac. canister. repaired the tank and replaced the hose. checked the check valve, checked for VACUUM at the carb., reinstalled all of it. It still had a hard pedal, but stopped if you plan ahead (so quick stops). After driving a while, it seems as if it has improved (or I got used to it). Thought about changing the system, but while I am still in the process of paint and upholstry etc., just trying to solve the problem. Seems everything is in order; but, not wonderful. Good luck. If I find a solution, I'll post.

 

thanks Tedd - good price all around...I'm going to pull the trigger on this probably this week - just trying to do a little more homework

I'll post the entire process

 

If anyone is interesting in learning something / sharing my pain / laughing at me, I'm starting a new thread on retrofitting the '55 with modern booster and master under the floor...