My Manual brakes Are Horrible...Help

[prairiehotrodder]

There you have it folks!! thanks guys. Question-- that factory manual brakes car, was the hole in the firewall the same size as power brakes cars? If so, what covers the hole?
Now.... what master do I need hmmmm.....
Brian

 

[Killerdave8813]

Hey, Just to throw my 2cents in I think StreetBu has the answer,check your master cylinder bore size,sounds trivial but it makes a big difference! I've had many vehicles with manual brakes and never had a problem stopping them and a Malibu isn't any different,you have something there mismatched and it's more than likely the MC,also the so called proportioning valve a they call it is actually just a distribution block and a place to hook up a low pressure warning light to let non mechanical/non drivers know they have a brake failure that needs to be addressed,I can remember having a 67 Chev pickup we drove for a while and ended up stripping for parts,4-wheel drum,dual reservoir master cylinder,small one actually( MC that is ) no proportioning valve,
actually I just remembered I've seen it called a combination valve which makes more sense,It had one 1/4" line to the rear brakes,one 3/16" line to a brass tee splitting off to the front drums and it stopped fine till my little brother got drunk and put it in to a creek one night!!
He was ok by the way,truck was pretty much not! But there's no reason in the world why manual brakes won't work on a Malibu!!! Get the right MC ant I bet it'll stop fine! Later,KillerDave

 

[prairiehotrodder]

From the pic by greendragginbu, it appears that the manual master has a much bigger base that covers the large hole in the firewall. Yet when i bought my master, i ordered from a parts store a stock manual brakes replacement master and it is an aluminum quick-take-up design and I had to use a block-off plate to fill in the rest of the hole. Also its funny that the factory manual brakes car has a smaller one-foot pedal.
Brian

 

[t5montecarlo]

The non-power brake pedal is the same as the manual transmission brake pedal.

 

[GreenDragginBu]

Yeah, I agree with the theory of the master cylinder bore size being culprit.... But, why have so many others purchased the same kit for their g-bodies and not had the same complaints??? thats the puzzling part.

Prairehotrodder, My car that had the factory manual brakes comes with a factory firewall block off plate with a X design embossed into it.. it looked just like this.

T5Monte does the g-body manual trans brake pedal have a higher pedal than a power brake automatic car???

the reason I ask is on my Bu that had the manual brakes, i thought the pedal was from a manual trans car too, but it was deffinetly higher than a automatic power brake car pedal is.

 

[t5montecarlo]

The pedal is the same, but with manual brakes, you need to use the upper hole (different dia pin). The same pedal, when used with a manual master, should sit further away from the firewall than the power brake pedal. I make that claim because that seems to be the case with all manual brake cars I have seen, but have not measured it on a 1978-198x Malibu. I have only seen 1 manual brake malibu (in a wrecking yard about 20 years ago), and I have the brake pedal.

 

[prairiehotrodder]

Is there a few different manual brake masters that the parts stores sell? Maybe every chain parts store has one a bit different bore size. Mine is alum with a very small resevoir yet most guys seem to have an iron master on their cars. I never measured the bore size on mine but now i'm really curious.
Brian

 

[GreenDragginBu]

Is there a few different manual brake masters that the parts stores sell? Maybe every chain parts store has one a bit different bore size. Mine is alum with a very small resevoir yet most guys seem to have an iron master on their cars. I never measured the bore size on mine but now i'm really curious.
Brian

I think different companies use different suppliers. Of the two parts store manual brake master cylinders I have bought, none seem to have the deep pushrod hole in them like the factory ones did. or shall i say like i have heard they are supposed to have. I wish i would have took mine apart on my manual brake bu just to know.

Or was they setup just like the manual brake S-10's with the push rod retainer????
like this

 

[Malibuwagon80]

Yes my front brake line just uses a brass T to split the line. I did away with the factory prop valve, the first time i did the manual swap(oem manual master, rod upper hole).

The reason for large variation in parts.. Was because i was trying to get a decent braking setup, so i replaced everything on the car trying to track it down.

I am currently using the original upper hole on the pedal instead of the one I drilled.

This interesting. You guys are having hard luck with your manual brake conversion, yet in other threads they are very satisfied. Perhaps bad parts is part of the problem?

That is one of the most frustrating parts, I see so many people do the swap with great results... and mine is sub par.

I'm starting to think you're problem might be the proportioning valve. The valve distributes different amounts of brake pressure to the front and rear. If I remember correctly I think you put a wilwood proportioning valve in. If you did try increasing the pressure to the front brakes. A friend of mine had one in an early vette that had manual brakes and it did wonders. He used to auto cross the car. My wagon still has the factory lines and proportioning valve in it. My brakes are ok I can line lock the car but have to pump them hard. I'm putting a bottle on the car and will see how it stops after spraying :-k . May be looking to put strange front brake setup in for next year :lol: Hope you get it straightened out!! Wagondude

 

[Fat Rat]

Supe, I have the same problem, after installing the kit from Travis. I can't see how it's supposed to work...both pedal ratio and MC size seem to be wrong according to the experts. Ideal pedal ratio is about 6:1, with the rod in the middle hole we have about 3:1. Stock size MC for Malibu is 15/16th's, MC that comes with kit is 1and1/8th i believe. Less pedal ratio, less MC pressure ??? ; I don't see how it's going to work. I don't know what to do any more, I worry about stopping in a panic situation. I hope someone out there can help us out.