Getting rid of booster

gt601 · #1 (**permalink**) 08-25-2006, 05:05 AM

Has anyone switched over their car to a boosterless setup??
I am getting tired of replacing the booster on my 77 Alfetta. I have put 4 used boosters on this car and they all have gone bad. I really don't want to spend the cash on a new one if I can get rid of it. My 78 X1/9 had no booster from the factory and it stopped great with very little pedal effort.
What would be the piston size/stroke of a replacement master cyl. that would have good stopping power without the booster? AND where can I source the stuff to do it?

Any help with info would be appreciated.

Paul

gt601 · #2 (**permalink**) 08-26-2006, 02:08 PM

C'mon... throw a dog a bone!

bianchi1 · #3 (**permalink**) 08-26-2006, 03:45 PM

i have my 4 piston calipers on my car. with the boster brakes are way to touchy. i will give my car a try without the boster today, on reg, brakes, will post later.it should be ok, on reg. brakes, just a little more pressure on the pedal, but more feeling.

**papajam** · #4 (**permalink**) 08-26-2006, 04:44 PM

Simply disconnecting the booster vacuum hose will result in brake pedal effort that is way too high. Too high to be driven safely, IMO. The booster would have to be removed and an appropriately sized master cylinder be fitted to some kind of bracket. Never did it before but perhaps one could just gut the booster?
I guess the real question is why have five boosters gone bad. Master cylinder leaking fluid into the booster? Bad vacuum hose check valve? Bad used boosters? I think I'd try to determine the root cause for the booster failures rather than address the symptom by binning the booster.

Alleggerita · #5 (**permalink**) 08-26-2006, 06:08 PM

If I remember correctly old 105 series cars without booster had a 3/4" or 20mm MC and those with booster had either a 7/8" or 22mm MC. I am not sure but Alfetta calipers may have similar piston diameters on the wheel cylinders.

I agree with papajam that a 22mm MC without booster requires too much pressure for normal usage, though it will do in an emergency. For a road car I would try to fix the problem, namely replace booster and MC at the same time with new items. On a racecar dumping the weight of the booster is nice.

**papajam** · #6 (**permalink**) 08-26-2006, 06:25 PM

Quote:

Originally Posted by Alleggerita

If I remember correctly old 105 series cars without booster had a 3/4" or 20mm MC and those with booster had either a 7/8" or 22mm MC.

gt601 · #7 (**permalink**) 08-27-2006, 10:53 AM

I'm using boosters from cars that have been sitting in fields for 20 years. They were free and they were shady to begin with. In my opinion the easiest thing would be to get rid if the booster and master that I have and make the appropriate mounts and linkage. I guess that at this time I need to know if anyone has done the math to figure out what diameter MC I would need to make enough pressure w/out the booster to make the pedal not so hard. I liked the way my X stopped and that it had a bit of a hard pedal. The brakes were really easy to regulate. That little sucker stopped on a dime.
Do You thingk that the 23mm mc that performatek has would be large enough??
More thought and opinions welcome.
I'm going out to the garage and take one of the bad ones apart and see what is failing.
Thanks
Paul

**papajam** · #8 (**permalink**) 08-27-2006, 12:49 PM

Quote:

Originally Posted by gt601

Do You thingk that the 23mm mc that performatek has would be large enough??

Alfapaulic · #9 (**permalink**) 08-27-2006, 08:01 PM

gt 601, What do the brakes feel like now? My spider had a bad booster which I replaced, and I think I liked the brake feel better before replacement!

gt601 · #10 (**permalink**) 08-28-2006, 04:01 PM

Ahhh I see.... I wil try this and see if it works. I would think that the pedal would feel the same with a bad booster as it would feel with no booster because the rod goes straight through. Right??

I took one of the boosters apart yesterday and the diaphragm was split at the edge of it.I may have resigned myself to just go ahead and buying a new one if I can't get through to ATE.
Paul

BlpltGTV · #11 (**permalink**) 10-30-2006, 01:17 PM

This is sort of on topic, I have a bad booster in my 69 GTV, I pulled it apart, replaced all the seals and it still leaks fluid from under the small diaphram. Is this the nature of the creature or do I need a new booster? How much work is it to change over to a single circut system from an earier car (John Norman's suggestion). I'd even be game to ditch the whole power brakes and run unassisted like my other car if that were easy to do.

Thanks,
Will

gt601 · #12 (**permalink**) 10-30-2006, 03:19 PM

Are you saying that the master cylinder is leaking into the booster? If it is I would replace the master cylinder before it too ruins the diaphram. When I took mine (the bad one) apart it had a bit of brake fluid in it which didn't help the rot factor. They were all just too old to re-use. I ended up just buying a new one from DiFatta. It is a joy to drive now with a good booster. It also idles better w/out a great big vac leak.

**papajam** · #13 (**permalink**) 10-30-2006, 05:00 PM

Although many Alfisti consider a variety of fluid leaks from a variety of locations to be somewhat normal, a leaking booster is not one of them.
I see a few options;
1)Determine exactly where the booster is leaking and fix it.
2)Install the good booster in the front brake circuit and leave the rears unboosted.
3)Bypass both boosters.
4)Buy a new/used booster.
5)Switching a tandem brake circuit to a single circuit is, IMO, NOT an option!

darth dino · #14 (**permalink**) 10-30-2006, 08:08 PM

Quote:

Originally Posted by BlpltGTV

I pulled it apart, replaced all the seals and it still leaks fluid from under the small diaphram.

**Wil Painter** · #15 (**permalink**) 10-30-2006, 09:19 PM

Will:
I'm running the '69 dual MC in an unboosted system in a vintage race car, with an adjustable proportioning valve in the rear circuit. Works great for that application, but then coming into a tight corner after a long straight naturally tends to boost my braking foot

so I can't judge what it would be like in a street application. I do like the firm, linear pedal feel on the track, and it seems fine in the pits.
All components of my system are new, hard pipe, steel braid hose, AN fittings, and a resleeved/rebuilt MC, so nothing leaks.
I know the '69 system was problematic for many, but I'm with Jim, I would not disable the dual circuit. Locate the leak and fix it, with or without boost. Osso has a great thread in this section of the BB on repairing the 69 MC, including the sleeving option. I would start there, as it is the heart of your system, and the source of many of the 69's issues.
Osso used Karps, I used White Post for the MC refurbishment. Jim (Papajam) occasionally does this service as well; you could do no better if he'll take on your project.
Wil