Vacuum line for Brake Booster-Pictures. Dial Up Warning

[MrMootsie]

I'm still a bit clueless on this, so I decided to post some pictures.

Here is the manifold side of the engine. You can see the new booster in the upper right.

Somebody please point to where I need to do this. Can I run a "T" off the fitting for the transmission?

Here is the carb up close. Any unused vacuum ports?

Last picture is of the plug side, just in case.

I need to be hit with a clue missile, please.

 

[fordconvert]

I would start off with a plastic 'T' in the transmission line. If thats not enough (because if its smallish size) then put a T in the PCV line. Make sure you have the check valve in the line between the booster and where you T in.

On my 66 the line for the transmission reduces in size a bit and changes to hose on its way down the firewall. I was planning on cutting off the reduced part and getting a T with differnt sizes so the max size would go to the booster and the orignal size goes to the transmission.

You can get the T's at parts stores usually near the misc hardware and fastner area or in the Motormite 'Help' section.

Some of the 'upgrade kit' boosters seem to claim that they are specially designed to run with the I6 so thats why I hope that it will run on the transmission line since a stock I6 does not have many choices.

If you loose boost after repeated braking next step would be to get a vac resivor from one of the performance places. They use them when they upgrage cams and vac is low... and again make sure the check valve is in the right place, in this case between the resivor and T.

 

[MrMootsie]

thanks

 

[addo]

Don't take the vacuum off the carb. Take it from the manifold. Also use vacuum rated hose. Earl's and similar will suffice if you want something flashy. The size of hose fitting on the end of your booster's check valve is a good indicator of what bore hose to select.

You may use steel line with just a short length - maybe 6" to 8" - of rubber at one end (bead the cut steel end for a good seal). An all metal line will not allow movement due to the engine vibrating on its mounts.

Light use of a non-hardening sealant such as Permatex #3, on hose fittings, will assure tiny leaks are not present. Don't swaddle the hose fittings with those fake Earl's cosmetic covers as a bad backfire occasionally loosens a hose and you then may not see the problem... Keep it simple and functional.

Regards, Adam.

 

[Anonymous]

Mine is tee'd into the PCV line as well. Works perfect, always have MEGA brake action success.

Red arrow = PCV valve

Yellow arrows = hard steel brake booster line (factory)

Green arrow = "T" where booster line connects to PCV line

yellow "X" is the brake booster

 

[MrMootsie]

Make sure you have the check valve in the line between the booster and where you T in.

What does this mean?

Awesome picture thanks. I'm getting to about 90% comfortable doing what I need to do.

Perhaps somebody can use my first picture above, and put an arrow where the T should go.

Yes, in fact, I am a moron.

 

[fordconvert]

Just to clairfy for those keeping score and to give detail to Adams post for those that have not been around engines all their lives....

Some carbs (especially after 1967 and 2bb and 4bbl) have multiple vac ports to operate various things usually emmision related. They often do specific things at specific times like contorl the advance in the dizzy and EGR valves. That is what Adam was talking about not using a carb port for brake booster. Rochester (GM) carbs usually had a 3/8" port in the back just for the brake booster. Im not sure about other brands but if you want to see a mess of ports and hoses look at a late 70's gm car with a Quadrajet, there has to be at least a dozen ports on the carb for all the emissions stuff. The carb in question in this case is a 1100. The only port on it is the steel line you see in the pic coming off the side about 1/2 way up the side of the carb. That line is the one that goes to the dizzy. I think there is a sticky that talks about how that works. On the stock 200 in the picture the only other ports are where the PCV valve hooks on which is that spacer plate mounted between the carb and intake. On this vintage 200 it also has the heater hose pass through it. In the picture it is a black hose you see wrap around the valve cover. The other one is a threaded hole in the intake that in the picture is below the carb and has a steel line that goes up and loops around a heater hose then bends down and leads to the firewall and then to the automatic transmission. Both of these are 'manifold' ports because they are after the carb. On V8's you will see things like PCV that are constant 'leaks' so to speak going into the carb because they want to distribute the 'leak' over all 8 cyls. Things like the heater controls, cruise control and transmission will often be a 'T' fitting near one of the runners in the corners. These devices dont use much vac so leaning out one cyl is not an issue. Also closer to a cyl the vac will have a pulse to it due to what part of the stroke that cyl is on. Some devices will have a problem with this some wont. Most of the more sensitive things will have a special port on the carb.

Anyone have anything to add or correct? Just thought I would explain further for those that are confused or afraid to ask 'dumb' questions.

 

[fordconvert]

I have not yet masterd working with pictures on websites. Looking at my spelling maybe I should learn?

The check valve is a plastic thing that goes in-line between the booster and your vac source. The brake booster has some reserve in it just in case you happen to need to brake during a low vac situation. The check valve is a 'one way' valve that will keep vac pressure in the booster if the engine pressure drops. The vac pressure changes depending on load, rpm, timing, throttle postion, and many other factors. You can test that on any car by pushing on the pedal with the engine off. You should get at least one 'normal' stroke. Many of my cars will give you about 2 1/2 strokes before you run out.

You can put the T anywhere in the line that is easy. The check valve goes in the hose that runs from the T to the booster. If you put the valve in backwards you wont have any vac to the booster so all you got to do is switch it the other direction and you should be in buisness.

 

[MrMootsie]

got it. Is it the line going from the spacer to into the valve cover on my first picture?

 

[fordconvert]

Yep thats it. If it worked for Linc it should work for you.

How did the booster install go so far?

If the kit didnt come with a check valve you should be able to get one out of the Motormite 'HELP' line at any store. Some even have some sort of a drier/filter thing in the same part.

 

[MrMootsie]

pain in the ass, actually. The bolts on the driver's side on the firewall are nearly impossible to tighten. I had to use an offset wrench. Big fun tomorrow will be putting the pushrod back onto the brake pedal and switch. This means I'll be upside down under the dash....again.

I assume there isn't a checkvalve inside the booster, correct?

 

[fordconvert]

I have never seen one in a booster.... but I have not seen them all.

This is what I am used to, it fits into the gromet on the booster. There are some that just go inline like a fuel filter but I cant seem to find an example now.

http://www.dormanproducts.com/cgi-bin/v ... ry_list=:0


mmmm.... I will be awaiting the full report on the booster..... Maybe manual drums are not so bad???

 

[wsa111]

As Linc said if it works ok.

By the book, the power brake booster should receive direct intake vacuum.

The pcv should receive a separate vacuum supply.

Put a vacuum guage on direct manifold vacuum & also guage the vacuum at the tee off the PCV line. The PCV is a controlled leak where the hose to the booster should be full manifold vacuum.

As Linc said if it works go for it, otherwise drill & tap a direct vacuum source from the intake log. William

 

[MrMootsie]

drill and tap....great.

 

[Anonymous]

The reason it will work in the PCV line is because the PCV is a restriction.

Sure, there is air flowing through the line, but it isn't like the PCV is a wide open 3/8" hole open to air. The little disc inside gets sucked up under vacuum and cause a restriction, so anywhere in the 3/8" hose is essentially "full manifold vacuum".

The brake booster only needs to be "charged' with vaccum, it isn't constant flow, so there is numerous opprtunities for full vacuum to build up in the brake booster....

...like the first time you let off the gas when decelerating.

Even then, brake boosters are designed to run fine all the way down to about 8" vacuum, so anything more than that (vacuum) isn't going to make it brake "better".

 

[MrMootsie]

okay..on the way to autodiscountpepzone for vacuum line, T and check valve. I'll let you know how it works.

 

[Zorm]

I'm not sure if it right but for my booster, I have the vac coming from that port on the intake log, below the carb, its in the first picture and on the bottom center of the second picture. Right before it goes into the booster, it is t'ed off and goes to the tranny I assume, seems to work ok, this is how I got the car, I did not run that line.

 

[Anonymous]

I'm not sure if it right but for my booster,

As long as your booster is seeing manifold vacuum you are golden

 

[MrMootsie]

line tapped, Master Cylinder bench bled and installed.....leaks at the banjo bolts. Tomorrow I need to go out and get more 10mm copper washers. Bob at Stainless Steel Brakes said that occasionally you have to double up on the crush washers to get the right seal.

 

[Anonymous]

ah brake bleeding what fun :roll: