Master cylinder bore size for hydroboost brakes

[bigmuddy]

Thanks, Oldtimer, I believe that is the one.

Will have to sit down tonight and start reading and mumbling to myself.

Easy road would be just to buy the kit from Wild horses, but that price just isn't in the budget. Too, I am not sure it would mount to the firewall with the lightning upper intake anyway as it.
The lightning upper intake on the 94 trucks the TB came out on the drivers side FYI which creates a whole other issue with room misc system brackets.

 

[bigmuddy]

That looks like one of @catfan's brackets. Maybe he can tell us whether it changes the pedal ratio or not.

Todd Z.

Yes it's a catfan unit.

 

[Oldtimer]

Do you have stock or aftermarket hood?
If aftermarket, picture of underside, to under stand clearance constraints.

 

[bigmuddy]

Aftermarket fiberglass. It has a rib that will contact if I go further forward.

If I thought it would clear the upper intake, I would consider coming straight out of the firewall with a 96-02 hydroboost unit that uses the stock angled bracket, then run my old master and go from there. Remans are 175.00 on fleabay. tried the local Oreillys parts store and they have one in stock for $360 + core charge. Ridiculous!

 

[Madgyver]

Amazon has cheaper astroboost units.

 

[bigmuddy]

Thanks Mad, yeah no way I am buying that from a local parts store..

 

[ntsqd]

I'm running one out of the JY on the Wagon. Flushed it 6 ways from Sunday and bolted it on. Might have cost $100.....

 

[bigmuddy]

OK, placed an order to show Monday from Amazon for a new 96-2002 boost unit with angled mount bracket.

Going to put all of this on hold until it shows, if I can mount directly to the fire wall I will go that route.

Stay tuned!

 

[catfan]

That looks like one of @catfan's brackets. Maybe he can tell us whether it changes the pedal ratio or not.

Todd Z.

Oldtimer linked the thread where this was addressed and yes it does change pedal ratio but I have made changes
to the bell crank since then .

 

[bigmuddy]

Oldtimer linked the thread where this was addressed and yes it does change pedal ratio but I have made changes
to the bell crank since then .

Dang it, so I have the old style. Can you elaborate on what needs changing as I am not going to ask you to do anything with the one I bought, I have had it for awhile...

 

[catfan]

Dang it, so I have the old style. Can you elaborate on what needs changing as I am not going to ask you to do anything with the one I bought, I have had it for awhile...

The brake pedal side tab was shortened and the bracket side tad is longer . The bell crank was angled to make it possible .
The change was made over a year ago and no feedback either way .

 

[bigmuddy]

The brake pedal side tab was shortened and the bracket side tad is longer . The bell crank was angled to make it possible .
The change was made over a year ago and no feedback either way .

Left another PM. thanks

 

[bigmuddy]

Ok, so I bought a new smaller mount from catfan (thanks catfan!)

I also bought a new safari/astrovan hydroboost see pics.

couple of things:
As you can see I am missing some internals on the hydroboost?
Can I swap the old hydroboost guts from the old to the new?
How does the connection length look on the new bracket and boost unit?

TIA

 

[toddz69]

Ok, so I bought a new smaller mount from catfan (thanks catfan!)

I also bought a new safari/astrovan hydroboost see pics.

couple of things:
As you can see I am missing some internals on the hydroboost?
Can I swap the old hydroboost guts from the old to the new?
How does the connection length look on the new bracket and boost unit?

TIA

Everything should swap over just fine.

Todd Z.

 

[ksagis]

Todd is most likely correct that the parts will swap but check the two bores. The spider thingy is specific to the power piston bore. One bore is about 1.6” the other I have seen is about 1.8”

 

[Oldtimer]

As you can see I am missing some internals on the hydroboost?

TIA

"The Girls" have the parts you need.

Hydroboost Brake Booster Repair Kits

Repair Kits for Hydroboost Brake Boosters. Power Brake Sales is a family owned and operated business specializing in affordable brake system repairs since 1948. Providing new replacement parts as well as remanufacturing services.

powerbrakes.com

 

[bigmuddy]

"The Girls" have the parts you need.

http://[URL]https://powerbrakes.com/hydroboost/repair-kit/

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View attachment 952176

Thanks, silly me I assumed when you bought a new brake booster it would come fully functional !

 

[bigmuddy]

So I cracked the old one open to retreive the internals and move them to the new unit. They are both 1.6 internal diameter.

I wasn't expecting all of this though from the videos I have seen online.
I hate to crack the new one open and take a chance on ruining the seals but I guess that has to be done to add the new internals? Correct?

 

[bigmuddy]

Todd is most likely correct that the parts will swap but check the two bores. The spider thingy is specific to the power piston bore. One bore is about 1.6” the other I have seen is about 1.8”

Matching 1.6 for these two.

 

[Oldtimer]

If you are missing the parts shown in post #36, they all are replaceable with out disassembling the hydroboost. Go to the powerbrakes dot com website, and read their tutorial on trimming and installing the pushrod.