vacuum assisted brakes

The connector at the booster where the hose connects has a one way valve built into it...

Like this.

John

Barry, if the plastic push-in valve/hose connection goes bad, it sometimes lets engine oil (via the long hose from the intake manifold) up through the valve and inside the booster. The oil attacks the large rubber vacuum diaphragm and over time can cause failure. In our Benditalia boosters, the diaphragm is not home-replaceable as a separate part. So its certainly worth pursuing this problem. Many power brake boosters use the same valve.

That check valve does go bad. I just changed mine.

Thanks alot everybody for the help !
I will check that valve tomorrow , didn't know it was "build-in" at the booster connection.

Is always scary , not that one has no brakes at all, but alot less then expected

quote:

Originally posted by PanteraDoug:
That check valve does go bad. I just changed mine.

Panteradoug , do you happen to have a brand/part # ? My shop doesn't know the origin, perhaps Alfa Romeo ??
Most know here are the plastic "push-in" types , angled or just plumbed in line. Seems we have a luxery model

mine is still perfect "clean" inside , but want a new one ofcourse to see if the problem is solved ....

quote:

Originally posted by Belgiumbarry:

quote:

Originally posted by PanteraDoug:
That check valve does go bad. I just changed mine.

Panteradoug , do you happen to have a brand/part # ? My shop doesn't know the origin, perhaps Alfa Romeo ??
Most know here are the plastic "push-in" types , angled or just plumbed in line. Seems we have a luxery model

mine is still perfect "clean" inside , but want a new one ofcourse to see if the problem is solved ....

No I don't. I just went and bought it from Wilkinson. Some say it is the same as from a Fiat but I would not know the model/year it came from.

This is the link. Wrong picture but right part.

http://www.panterapartsusa.com...l.cgi?prod_id=01337a

Thanks alot ! i see at a local Fiat/Alfa shop and if not i go Wilkinson....

I would take the part with me and see if they can match it up. It probably is a common part for them and should have one in the store.

The only problem with Wilkinson is the time delay to get it because of shipping, and he charges you for handling.

i have already the part in my daily
everything must match, dia bolt and flexible.
Have cleaned it with some gasoline and air pressure.. could be "OK" again.
Another solution would be using it again for the booster connection and a supplementary "in-line".....we will see no big problem.

I got today !!! my license plate
up till now i was still riding the UK plates / Insurance from the former owner. But there's a new law ,forbitten this and they hunt foreing plates...so i had to do something .One problem was the adjustable suspension, Ok, for now, but as you know i bought my Insurance with originals on spare..Bit embarresing for me , i did the wire transfer monday a week ago and Dave didn't see the payement yet ... now almost 2 weeks !!!! .. I think they flying it over the pond bill by bill

quote:

Originally posted by Bosswrench:
Barry, if the plastic push-in valve/hose connection goes bad, it sometimes lets engine oil (via the long hose from the intake manifold) up through the valve and inside the booster. The oil attacks the large rubber vacuum diaphragm and over time can cause failure. In our Benditalia boosters, the diaphragm is not home-replaceable as a separate part. So its certainly worth pursuing this problem. Many power brake boosters use the same valve.

How can I check if the plastic push-in valve is working properly?

Anders,

just get it out and air pressure test it. Ofcourse it should only let trough one way and be 100% tight closed the other

I figured it out myself when I had gone to bed and start thinking. :-/

Is there anything special pressure valve should be able to take?

I'll put up this to the check list before every season.

One year I forgot to tighten hose clamps for vacuum hose, became very surprised when I start brake and thought that the brakes didn’t work at all. It was not funny at all…

Besides checking the valve for function, its a good idea to occasionally check the entire system. Disconnect the hose at the intake & put a vacuum on it. The vac-hose sections at the front & back of the under-car hard line tend to crack from oil inside, usually in an area where they can't be seen. Occasionally you'll find a Pantera where someone has substituted cheaper fuel hose for nice stiff vac hose, and the more flexible fuel hose collapses under vacuum.

I don't have a vacuum gauge, but I've been thinking of buying one. Which vacuum gauge do you recommend?
Those I have found in Sweden are cheap "non name" gauge.

I have thought I put on original air cleaner and stock crankcase ventilation, it is better to put the crankcase breather hose on its own nipple, than a T connector on the brake vacuum hose?

cleaned it with gasoline and air pressure , seemed OK .
But today we did a trip to Bruges , included a Irish rib eye , but a few times the same, no assisted braking.
So must look for a new one ....
On a open road there was a 911 who tryed... but showed him my big rear

There is a rubber seal inside the booster. Mine came out of place and I was getting intermittant power assisted brakes.

is it home-replaceble ? as Bosswrench mentioned the rubber diaphragm which seems not...

The Pantera unit is very similar to the American Bendix unit.

It is crimped together. There is nothing servicable on it from the outside.
It needs to be disassembled to do that.

That big grommet that you see through the push rod port is actually part of the big rubber diaphram. At least it is in the Bendix unit.

They can be disassemble without damaging the case but you need a special jig to hold it and a hydraulic press with an adapter for it.

Harmon Brakes in California does them. Gets about $150 to do it.

He has all of the jigs and parts for them.

There is another unit used here on Fords called the Midland.

It is disassemblable with a large removable clamp on the exterior.

I just did one of those and screwed it up. Some of the internals are made out of bakelite. It is fragile and brakes very easily.

Nothing for a bull in a china shop should attempt. Those parts are no longer available from anyone.

if i'm right , there seems to be 3 places were vacuum can be lost if ofcourse the check-valve is working properly and the casing isn't corroded trough .

1) at the "seal-valve" inside, one opens at braking...if that doesn't close all the time 100 % , could be the problem

2) at the brake cilinder connection ( rubber seal ? )

3) ofcourse the diaphram itself...

The diaphram itself seems to have a life expectancy of 40-45 years.

Mine was broken through the "crease" in three or four places.

Would it be a good ? idea to spray some WD40 at the air inlet = at the brake padel pushing rod entry... and pumping brakes with engine running .
Just to get that inside seal-valve a bit misty oiled ???

Typically the rubber components in these assemblies do not like petroleum based substances. They tend to swell the rubber and do not lend to lubrication properties at all.

You want to keep petroleum based fluids away from the diaphram as well as brake fluids.

The boosters do not need lubrication.

They have internal components that are made from naturally slick materials.

So the answer is no, it is not a good idea. If they are holding a vacuum, leave them alone.

quote:

Originally posted by PanteraDoug:
Typically the rubber components in these assemblies do not like petroleum based substances. They tend to swell the rubber and do not lend to lubrication properties at all.

You want to keep petroleum based fluids away from the diaphram as well as brake fluids.

The boosters do not need lubrication.

They have internal components that are made from naturally slick materials.

So the answer is no, it is not a good idea. If they are holding a vacuum, leave them alone.

Ok , Sir, i won't do it