Chevy front disc conversion mustang hydroboost mastrr cylinder

[G's Baja Bronco]

Any one using a Chevy disc conversion with the 99-04 mustang gt HB and MC ???

I have bleed the system perfectly and the brake rod is perfect also. I get the rear explorer discs to lock and the front chubby get too little a pressure. I can even see when I bleed them, the front comes out slowly, usually a strong spray is seen, specially with HB. Not on mine.
We have the exact same combo on my bros 73 with front 77 ford discs and rear drums and the snap your neck when breaking.
We assume that the chubby caliper require more fluid than the ford.

I wonder if the super duty f250 MC will work. Any one know the mounting and bore size??

 

[G's Baja Bronco]

Threading new ground again!

 

[Broncobowsher]

Are the bleeders on top? Probably the most common mistake with the chevy brake conversion.
Front resivior to rear brakes, rear resivior to front brakes

 

[G's Baja Bronco]

Are the bleeders on top? Probably the most common mistake with the chevy brake conversion.
Front resivior to rear brakes, rear resivior to front brakes

Yes, bleeders om top. I will swap the connections to your recommendation, since the rear MC connection has the most pressure i will feed the front disc with that. since the front MC connection has less pressure, I will feed the rears with that.

I wonder if ford designed the braking pressure ration into the MC?
specially since the prop valve (stang) is pretty much pass thru.
Thanks Bowsher!

 

[broncnaz]

Sounds like your issue is with the hook ups to the MC.
Kinda depends on the MC but some of the fords use a 2 piston design with a spring in between the primary and secondary pistons this will result in some bias or delay in braking to the rear.
Not real sure on a 99-04 mustang prop valve as it probably still has proportioning to the rear side as you cant have the rear brakes lock up before the fronts which easily happens due to weight transfer.

 

[G's Baja Bronco]

Sounds like your issue is with the hook ups to the MC.
Kinda depends on the MC but some of the fords use a 2 piston design with a spring in between the primary and secondary pistons this will result in some bias or delay in braking to the rear.
Not real sure on a 99-04 mustang prop valve as it probably still has proportioning to the rear side as you cant have the rear brakes lock up before the fronts which easily happens due to weight transfer.

That would explain things. The high pressure on the rear piston of the mc. Since it gets pressure front HB first. I have had the same results with the one I got from the bone Yard together with the HB and 2 new ones.
I am trying this next and will report back.
Tnkz broncoNaz

 

[G's Baja Bronco]

back to the drawing board.

any one here run the chebby front calipers with mustang HB and MC (99-04 gt stang)???

I swapped the connections and now the rear MC has the lower pressure and the front (now rear discs) has the high pressure. drove around and the rears lock up while the front ones do not.

I am now convinced that I need a digger bore in the MC. since the rear calipers are smaller taht the front and swapping the MC ports changed the spray force accordingly.

 

[G's Baja Bronco]

I am seriously considering the super duty MC and maybe even the HB to get the longer push rod from the factory. it's bore is: 1.375 vs the stang's 1".

 

[G's Baja Bronco]

http://www.4x4review.com/Features/Tech/HydroboostBroncoPart2/tabid/289/Default.aspx
the more I read the more I think I need a larger bore.

on my Bro's 73 with 77 ford calipers the 1" mustang MC is great, since the 77 EB had a 0.90" bore MC.

the cjevy caklipers I have came on a 75 or newer blazer with a 1.125 bore MC. again the stangs is a 1" bore.

the SDuty has a 1.375 bore. I am calling wrecking yards in the am!

 

[G's Baja Bronco]

taking updates to main build thread!

 

[Apogee]

http://www.4x4review.com/Features/Tech/HydroboostBroncoPart2/tabid/289/Default.aspx
the more I read the more I think I need a larger bore.

on my Bro's 73 with 77 ford calipers the 1" mustang MC is great, since the 77 EB had a 0.90" bore MC.

the cjevy caklipers I have came on a 75 or newer blazer with a 1.125 bore MC. again the stangs is a 1" bore.

the SDuty has a 1.375 bore. I am calling wrecking yards in the am!

My '77 EB has a 1" bore MC...not sure where you got your information regarding it being a .90" bore. You didn't respond to my PM, however it still sounds like something isn't functioning as it should, so swapping the MC may or may not fix whatever the actual issues are.

That said, moving from a 1" bore MC to a 1.125" bore is a 27% increase in area, meaning you'll get 27% more volume and 27% less pressure for a given pedal input force. If you opt for the 1.375" bore unit, that is an 89% increase in bore area...you sure you want to do that?

Not to beat a dead horse, but if your pedal feels funky/soft/mushy/inconsistent/etc, then there's something going on with respect to the booster or MC or there's still air in the system.

HTH,
Tobin

 

[Rustytruck]

if your running the large bore Blazer calipers then you will need the 1-1/8 bore master cylinder or it will take 2 strokes of the pedal to fully pressurerize the system. If your looking for a Ford mastercylinder look at the ones for the ford van if you want the ports on the passengers side of the mastercylinder.

 

[Broncobowsher]

if your running the large bore Blazer calipers then you will need the 1-1/8 bore master cylinder or it will take 2 strokes of the pedal to fully pressurerize the system. If your looking for a Ford mastercylinder look at the ones for the ford van if you want the ports on the passengers side of the mastercylinder.

You shouldn't need to upsize. I had very good success with a 1" bore MC mustang HB setup on GM disks.

 

[G's Baja Bronco]

Apogee, I just responded to the IM, my apologies, I have a hard time woth my new galaxy 3, my fat fingers are having a hard time with the keys, must have not sent it!

I picked up a hb/mc from a 04 f250 sd this morning, i returned the c6 and got credit, so no money for the SD parts.

I must have a defective stang HB or a 3rd bad MC, I have bleed a lot and finally the pedal is firm, but I still have to push 1/2 of the travel. I have the large blazer calipers ( rebuilt) and new ceramic pads, wen I drive the rears lock and eh fronts do not, I swapped mc connections and same effect.

The weird thing is that the visual pressure wen I bleed the MC in the truck:
the line feeding the rear has a lot of pressure (as I expect from HB) and the one feeding the front does NOT. regardless of the front mc feeding front or rear. this leads me to believe that the fronts need more volume.

I got the .90" from a website. i will install the SD goodies and report on what I find.

BTW, I am using all braided and coated hoses on the truck, I expected more firmness from them.

 

[G's Baja Bronco]

if your running the large bore Blazer calipers then you will need the 1-1/8 bore master cylinder or it will take 2 strokes of the pedal to fully pressurerize the system. If your looking for a Ford mastercylinder look at the ones for the ford van if you want the ports on the passengers side of the mastercylinder.

Rusty, are you running the Blazer calipers on the front?

I plan to use the MC from the SD.;D

 

[11wnb]

Hey G,

Did you check to make sure your front calipers aren't making contact with something? I remember there is a little clearancing involved with this conversion. You have to grind some material off the bracket and sometimes off the caliper itself.

 

[Rustytruck]

Yes I am running 1974 Blazer calipers. These would not work with a 1" bore mastercylinder. you ran out of stroke before the calipers reach full pressure. I use to run the 1-1/4 bore then changed to 1-1/8 bore when i went Hydra boost. Another Issue you may want to check is that your inner push rod from the Hydra boost to the master cylinder is the right length. with the system off push the peddle with you hand and feel when all the slack is taken up if the brake is right there the rod may be too long if there is alot of travel the rod may be too short limiting your ability to presurize the calipers properly. I dont use the mustang hydra boost I use the lincoln one but they all work the same.

 

[G's Baja Bronco]

Hey G,

Did you check to make sure your front calipers aren't making contact with something? I remember there is a little clearancing involved with this conversion. You have to grind some material off the bracket and sometimes off the caliper itself.

thanks for the tip, the conversion was done by the PO, and they worked wen I drove it home, they had a manual stock MC. all I did is get rebuild ones and new ceramic pads and steel braided hoses.

 

[G's Baja Bronco]

Yes I am running 1974 Blazer calipers. These would not work with a 1" bore mastercylinder. you ran out of stroke before the calipers reach full pressure. I use to run the 1-1/4 bore then changed to 1-1/8 bore when i went Hydra boost. Another Issue you may want to check is that your inner push rod from the Hydra boost to the master cylinder is the right length. with the system off push the peddle with you hand and feel when all the slack is taken up if the brake is right there the rod may be too long if there is alot of travel the rod may be too short limiting your ability to presurize the calipers properly. I dont use the mustang hydra boost I use the lincoln one but they all work the same.

thanks RUSTY, the super duty HB/MC swap is done. the brakes work perfectly now! I can now work on other areas of the build. was able to bring it uo to 60 mph and feel the OD shift!!! ;D;D;D;D;D