Wrong master cylinder - should I worry?

[RaeRae1]

Well, I know it has been forever, but I thought I would just post up a little update on the brakes.

They seem to be working. I played around with a lot of the vacuum lines. Replaced hoses that looked like they needed it and still had some issues. However, I ended up having the carb tuned/rebuilt because it kept stalling. Well, not only did that help the vert run better, but it also seems to have almost completely solved the brake issues that were left. Although they still don't seem quite right, they work excellently. The only problem I have now is that they seem almost too touchy!

Thanks again for everyones help!

[bobss396]

As Jed Clampett would say, "Welllll doggies!".

If you feel that it stops safely enough, so be it. Did you jack up the whole car and have someone try to spin a front and rear wheel when the brakes were applied?

Having the carb done over could solve a vacuum issue and make it stop better. Some power brake systems are touchier than others. If it were my car, I would change the check valve at the power booster to see if that made a difference. Unless it is already new.

Have you tried to block off the power booster line and drive it? I would be curious to see if it took away from the touchy condition.

Bob

[MagicRat]

Glad to read that the project is coming along. Sometimes, after replacing a master cylinder, the brakes are a bit touchy. Sometimes, this is due to an 'overboost situation due to a maladjusted power brake booster pushrod.

If you removed the master cylinder, you would see the end of the pushrod in the hole where the master goes. Turning it to move it outwards just a bit may fix the touchiness. However, I'm sure you are in no mood to work on the brakes anymore.... it's usually just fine to drive as-is.

BTW, what kind of carb is on this? If it's an Autolite 4bbl, you have, imo, one of the best carbs out there. They are great for smooth, seamless performance on a stock engine.

[joe68]

well i am glad to hear that, i was wondering how you made out, and the carb not producing enough vacum at times will play a big part on well it run or drive you nuts

[RaeRae1]

Originally Posted by bobss396

As Jed Clampett would say, "Welllll doggies!".

If you feel that it stops safely enough, so be it. Did you jack up the whole car and have someone try to spin a front and rear wheel when the brakes were applied?

Having the carb done over could solve a vacuum issue and make it stop better. Some power brake systems are touchier than others. If it were my car, I would change the check valve at the power booster to see if that made a difference. Unless it is already new.

Have you tried to block off the power booster line and drive it? I would be curious to see if it took away from the touchy condition.

Bob

It definitely stops well enough to feel safe now.

Yeah, we tried the "spinning each wheel" trick at the start of all this. The brakes always worked well enough to stop each wheel from spinning under human power.

I am still pretty convinced it is a vacuum issue somewhere, and being that the carb rebuild helped the problem substantially just verifies that more.

I have not tried blocking off the power booster. I might try that as well. Thank you again for all the help you gave me along the way.

I also replaced the check valve on the booster, that was also one of the first things we did.

Originally Posted by MagicRat

Glad to read that the project is coming along. Sometimes, after replacing a master cylinder, the brakes are a bit touchy. Sometimes, this is due to an 'overboost situation due to a maladjusted power brake booster pushrod.

If you removed the master cylinder, you would see the end of the pushrod in the hole where the master goes. Turning it to move it outwards just a bit may fix the touchiness. However, I'm sure you are in no mood to work on the brakes anymore.... it's usually just fine to drive as-is.

BTW, what kind of carb is on this? If it's an Autolite 4bbl, you have, imo, one of the best carbs out there. They are great for smooth, seamless performance on a stock engine.

Hahahaha. In the previous posts it shows how many times I have already removed and replaced the master cylinder. I have adjusted and readjusted the push rod several times. Perhaps if I get bored enough I will take it out and adjust it a little.... but not now. It ain't broke enough to warrant that.

I wish it were the 4bbl. No, it is the stock 2bbl. I have been tempted to go out and get a fuel injection system for it, or perhaps just go with a nice 4bbl. Not sure if I can find an autolite, what are your thoughts on replacing it with a Holley?

Originally Posted by joe68

well i am glad to hear that, i was wondering how you made out, and the carb not producing enough vacum at times will play a big part on well it run or drive you nuts

Absolutely!

[MagicRat]

Originally Posted by RaeRae1

Hahahaha. In the previous posts it shows how many times I have already removed and replaced the master cylinder. I have adjusted and readjusted the push rod several times. Perhaps if I get bored enough I will take it out and adjust it a little.... but not now. It ain't broke enough to warrant that.

I wish it were the 4bbl. No, it is the stock 2bbl. I have been tempted to go out and get a fuel injection system for it, or perhaps just go with a nice 4bbl. Not sure if I can find an autolite, what are your thoughts on replacing it with a Holley?

Okay, it's probably best to leave the brakes as-is.

As for the Holley..... what engine is in this, 302 or 351?

If you do go for a 4bbl, you will obviously need a new intake manifold.

A stock Ford iron 4bbl intake is okay, but the carburetor ports are a bit small and limit the variety of carbs that will fit.

An aftermarket aluminum manifold is much better, such as a "dual-plane" Edelbrock or Weiand model. There are lots of these used available at swap meets, so long as they are straight, not cracked etc. Ot they are available new for a reasonable dollar.


I am a big fan of Holley carbs. They are relatively simple, durable and extremely versatile. They can be tuned very easily to be used in a wide variety of situations.

They are not quite as sophisticated as most other 4 barrel carbs because their enrichment circuit (used to compensate for lower manifold vacuum) is relatively primitive compared to other cars, like the Rochester Quadrajet, Autolite etc. But they are so easy to tune that one can work around this.

http://www.holley.com

Holley has made literally hundreds of distinct carb models, based on 5 basic designs.

These designs are:

The 4150 and 4160 design.
-These are 'square-bore' models, where alll 4 barrels are the same diameter.
The 4150 and 4160 differ only in the way the fuel metering is set up for the secondary barrels. The 4150 is easier to adjust the fuel mixture for the secondaries, but is slightly more expensive to buy.
They have been made in many sizes from 390 CFM to 850 CFM.

The 4165/4175 :
This is a 'spread-bore' design, there the primary barrels are smaller than the secondary barrels, similar to a Quardajet and Autolite carb. The idea is that they will give better fuel economy for ordinary on-road driving. But their throttle response is not as linear as a square-bore design. When you open the secondaries, you get a more sudden power increase than a square-bore. This is fine fo rthe street, but performance/racing applications favour the 'squarebore' design.
They have been made in sizes from 650 to 750 CFM

2300 design:
This is a 2-barrel carb, its pretty much identical to a 4150, but without the secondary barrels. They come in 350 and 500 cfm.

The 4500 "Dominator" design:
Huge race-only carb, 1050 or 1150 cfm. Not for street use.

The 4360 design:
Strange-looking carb intended as a bolt-on replacement for the Rochester Quadrajet. It is not based on the normal 'modular' Holley design and is not very popular, and typically are rated at 450 CFM.

The first two designs shown above are the most common and the ones most often used. They can be bought with side-hung or center-hung floar bowls. The side-hung are cheaper and better for off-road use. The center-hung is better for street use with lots of high-speed turns. But for most regular sue, yo uwill not notice a difference.

These designs can use vacuum or mechanical secondaries. Vacuum is best for street use. The mechanical secondaries (often called "double-pumpers" due to their use of 2 accelerator pumps) generally are better for high-rpm racing.

You can get single-feed or dual-feed fuel inlets..... (dual is more useful for racing).... and mechanical or electric chokes. Electric chokes are more convenient but a bit more money.

So, what carb would I recommend for you?

For a stock 302 V8 or a 351 Windsor, I would suggest a Holley #1850 carb. This is a model 4160 carb, 600 CFM (cubic feet per minute), with vacuum secondaries. It's a perfect unit for a small block stock engine, or on ewith mild mods like headers, exhaust, mild cam etc.


You might want to get the electric choke option for this carb. It's more convenient and not much more money than a manual-choke model.

It is Holleys most popular 4bbl for good reason, and is quite inexpensive.

However, virtually all new Holleys seem to be jetted a bit rich for an all-stock 302. They will run great right out of the box, but might need a bit of leaning-out.

If you have exhaust headers on a 302, or have a 351 V8, the Holley jetting should be spot on.

But Holleys are extremely easy to tune. Slightly leaner jets are easy to get and easy to install.

BTW you will get people who claim Holley carbs are not good or use too much fuel etc. Imho, these people simply have selected the wrong carb, or do not know how to set it up.
For example, they may have a mild small block V8 but insist on getting a full-on race carb, like a huge 850 cfm double-pump carb then wonder why it does not work very well.
When you pick the right Holley for the job and set it up properly, they are superb.

[RaeRae1]

Originally Posted by MagicRat

Okay, it's probably best to leave the brakes as-is.

As for the Holley..... what engine is in this, 302 or 351?

If you do go for a 4bbl, you will obviously need a new intake manifold.

A stock Ford iron 4bbl intake is okay, but the carburetor ports are a bit small and limit the variety of carbs that will fit.

An aftermarket aluminum manifold is much better, such as a "dual-plane" Edelbrock or Weiand model. There are lots of these used available at swap meets, so long as they are straight, not cracked etc. Ot they are available new for a reasonable dollar.


I am a big fan of Holley carbs. They are relatively simple, durable and extremely versatile. They can be tuned very easily to be used in a wide variety of situations.

They are not quite as sophisticated as most other 4 barrel carbs because their enrichment circuit (used to compensate for lower manifold vacuum) is relatively primitive compared to other cars, like the Rochester Quadrajet, Autolite etc. But they are so easy to tune that one can work around this.

http://www.holley.com

Holley has made literally hundreds of distinct carb models, based on 5 basic designs.

These designs are:

The 4150 and 4160 design.
-These are 'square-bore' models, where alll 4 barrels are the same diameter.
The 4150 and 4160 differ only in the way the fuel metering is set up for the secondary barrels. The 4150 is easier to adjust the fuel mixture for the secondaries, but is slightly more expensive to buy.
They have been made in many sizes from 390 CFM to 850 CFM.

The 4165/4175 :
This is a 'spread-bore' design, there the primary barrels are smaller than the secondary barrels, similar to a Quardajet and Autolite carb. The idea is that they will give better fuel economy for ordinary on-road driving. But their throttle response is not as linear as a square-bore design. When you open the secondaries, you get a more sudden power increase than a square-bore. This is fine fo rthe street, but performance/racing applications favour the 'squarebore' design.
They have been made in sizes from 650 to 750 CFM

2300 design:
This is a 2-barrel carb, its pretty much identical to a 4150, but without the secondary barrels. They come in 350 and 500 cfm.

The 4500 "Dominator" design:
Huge race-only carb, 1050 or 1150 cfm. Not for street use.

The 4360 design:
Strange-looking carb intended as a bolt-on replacement for the Rochester Quadrajet. It is not based on the normal 'modular' Holley design and is not very popular, and typically are rated at 450 CFM.

The first two designs shown above are the most common and the ones most often used. They can be bought with side-hung or center-hung floar bowls. The side-hung are cheaper and better for off-road use. The center-hung is better for street use with lots of high-speed turns. But for most regular sue, yo uwill not notice a difference.

These designs can use vacuum or mechanical secondaries. Vacuum is best for street use. The mechanical secondaries (often called "double-pumpers" due to their use of 2 accelerator pumps) generally are better for high-rpm racing.

You can get single-feed or dual-feed fuel inlets..... (dual is more useful for racing).... and mechanical or electric chokes. Electric chokes are more convenient but a bit more money.

So, what carb would I recommend for you?

For a stock 302 V8 or a 351 Windsor, I would suggest a Holley #1850 carb. This is a model 4160 carb, 600 CFM (cubic feet per minute), with vacuum secondaries. It's a perfect unit for a small block stock engine, or on ewith mild mods like headers, exhaust, mild cam etc.


You might want to get the electric choke option for this carb. It's more convenient and not much more money than a manual-choke model.

It is Holleys most popular 4bbl for good reason, and is quite inexpensive.

However, virtually all new Holleys seem to be jetted a bit rich for an all-stock 302. They will run great right out of the box, but might need a bit of leaning-out.

If you have exhaust headers on a 302, or have a 351 V8, the Holley jetting should be spot on.

But Holleys are extremely easy to tune. Slightly leaner jets are easy to get and easy to install.

BTW you will get people who claim Holley carbs are not good or use too much fuel etc. Imho, these people simply have selected the wrong carb, or do not know how to set it up.
For example, they may have a mild small block V8 but insist on getting a full-on race carb, like a huge 850 cfm double-pump carb then wonder why it does not work very well.
When you pick the right Holley for the job and set it up properly, they are superb.

Wow! Thanks Magic Rat. A plethora of information in that post.

I have the 351 Windsor, and since it is a convertible, I am not planning on racing it. It is strictly my street baby. I was thinking the 4165/4175 would probably be the option I would consider. I was planing on getting an intake manifold too. I'm just waiting until I can afford it for now. I'm currently looking at 4 grand to repair the torque boxes and rocker panels (poor car was stored in a dirt floor garage for 14 years and the undercarraige shows it). So, more performance will just have to wait a bit I guess But I will definitely keep this in mind when the time comes. Thanks!