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Discussion Starter #1
I finished my f-350 brake upgrade and am having trouble. I put the F-350 booster and master cylinder on and the thunderbird calipers. I had trouble bench bleeding the master cylinder but put in on any way. I put about 1.5 qt. through the brake lines when I bleed the brakes. I didn't see any air come through. The brakes are not working. The pedle goes to the floor and the truck is not getting a lot of braking power at all. I have checked all my connections and there are no leaks.
What do you think?

Edit- I did adjust the rod that goes from the booster to the MS. I made it longer. Now the pedle doesn't go to the floor but it still doesn't stop well at all. Worse than before the upgrade (if possible)
 

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Discussion Starter #3
Gacknar said:
What problems did you have bench bleading the booster and where did you buy it?
I got all my parts from Car Quest. When I bench bleed the MS I put the plugs in the 2 ports and pushed the piston in and out. According the the instructions pressure is suposed to build up so you can't push the piston in more than 1/8". I pretty much didn't get any pressure at all. I did post a question a few days ago about the problems bench bleeding the MS. There was a suggestion that the MS was no good. I am still leaving that option open.
 

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bmboll said:
I got all my parts from Car Quest. When I bench bleed the MS I put the plugs in the 2 ports and pushed the piston in and out. According the the instructions pressure is suposed to build up so you can't push the piston in more than 1/8". I pretty much didn't get any pressure at all. I did post a question a few days ago about the problems bench bleeding the MS. There was a suggestion that the MS was no good. I am still leaving that option open.
Sounds like a bad Master Cylender to me.
What brand does CarQuest carry and is it a reman?
 

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Discussion Starter #5
Gacknar said:
Sounds like a bad Master Cylender to me.
What brand does CarQuest carry and is it a reman?
To be honest I am not real sure. I got the parts through a friend who has a relative........I got a good price.
The boxes have CarQuest lables so I assume they are reman. When I priced it out a few months ago I thought he said they were new. Like I said I'm not sure.
 

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No pressure = bad MC. Get a new one. Don't even try to install it if it doesn't build pressure during the bench bleed. Good luck :beer
 

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I never got pressure in any of my masters when I bench bleed them. I always had a set of hoses which cycled the fluid back into the master, you pumped the piston till air bubbles stopped.
 

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jopes said:
I never got pressure in any of my masters when I bench bleed them. I always had a set of hoses which cycled the fluid back into the master, you pumped the piston till air bubbles stopped.
You would if you plugged the lines like he was referring to. The method you mention makes better sense to me though.
 

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bmboll said:
I got all my parts from Car Quest. When I bench bleed the MS I put the plugs in the 2 ports and pushed the piston in and out. According the the instructions pressure is suposed to build up so you can't push the piston in more than 1/8". I pretty much didn't get any pressure at all. I did post a question a few days ago about the problems bench bleeding the MS. There was a suggestion that the MS was no good. I am still leaving that option open.
It is my understanding that plugging the ports and pressing the piston will not bleed the air from the cylinder, it has no way to escape, the cylinder should have come with fittings to attach hoses to the ports and return fluid to the reservoir. Then pumping the piston slowly watch for air bubbles to stop and you're done. Just be sure that the hoses are in fluid all the time wile doing this if not when you let go of the piston, it will suck air back in the lines. Hope this helps.:drinkbud
 

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It is my understanding that plugging the ports and pressing the piston will not bleed the air from the cylinder, it has no way to escape, the cylinder should have come with fittings to attach hoses to the ports and return fluid to the reservoir. Then pumping the piston slowly watch for air bubbles to stop and you're done. Just be sure that the hoses are in fluid all the time wile doing this if not when you let go of the piston, it will suck air back in the lines. Hope this helps.
this is true !!
 

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Discussion Starter #11
The instructions that come with the MS said "new and improved way to bench bleed the master cylinder". I do understand the concept of the other way. I was just following instructions. I guess the bottom line is I don't have brakes. Even if I didn't bench bleed it right I put a lot of brake fluid through. I would have thought 1.5 qts would have gotten any air out. Am I thinking right? I am in the works of getting a new MS and starting over again. I don't have the parts to bench bleed it the other way. Do they sell them at any auto parts place? How much?
 

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I don't think any amount of line bleeding will get the air out of a mc, been there tried that. Any auto parts store should have the parts necessary, shouldn't be to expensive they're only plastic, give it a try, it will work.
 

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You can always loosen the lines to the m/c and bleed it manualy with a second person working the pedal, that will tell you if its bad. when I did the upgrade I had the same problem, I had to start at m/c lines and work my way thru every fitting and coupler till I got to whe wheel cylinders. It was a PITA!!
 

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Discussion Starter #14
I got a new master cylinder today. I bench bleed it the other way this time, using the return lines to the reservoir. I have the same problem. The brake goes all the way to the floor and I get about a 50% braking.
When I was driving it I tried pumping the brakes a little before I really stomped on it. That seemed to build up some pressure. The peddle didn't go all the way down but I still didn't get very good braking.
What do you all think?
Don't be afraid to throw out ideas like, "are your sure your not hitting the gas instead of the brake?" because I am prone to do some stupid things.
 

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bmboll said:
I got a new master cylinder today. I bench bleed it the other way this time, using the return lines to the reservoir. I have the same problem. The brake goes all the way to the floor and I get about a 50% braking.
When I was driving it I tried pumping the brakes a little before I really stomped on it. That seemed to build up some pressure. The peddle didn't go all the way down but I still didn't get very good braking.
What do you all think?
Don't be afraid to throw out ideas like, "are your sure your not hitting the gas instead of the brake?" because I am prone to do some stupid things.
Have you checked your brake cylinders and calipers to see if there is any brake fluid leaking? You may have a bad rear cylinder or front caliper. :shrug How are you bleeding the brake lines once the master cylinder is reattached?
 

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Discussion Starter #16
JahWarrior said:
Have you checked your brake cylinders and calipers to see if there is any brake fluid leaking? You may have a bad rear cylinder or front caliper. :shrug How are you bleeding the brake lines once the master cylinder is reattached?
My wife pumps the brake then holds it down, I open the valve, fluid comes out, I close the valve, wife lets up on the peddle. Repeate several times.
 

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bmboll said:
My wife pumps the brake then holds it down, I open the valve, fluid comes out, I close the valve, wife lets up on the peddle. Repeate several times.
Are you starting on the rear passenger side, then rear driver, next front passenger, last front driver? Keep a CLOSE eye on the fluid level in the MC while you are bleeding too... You pull any air down in there and your back to square one.
 

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Discussion Starter #18
JahWarrior said:
Are you starting on the rear passenger side, then rear driver, next front passenger, last front driver? Keep a CLOSE eye on the fluid level in the MC while you are bleeding too... You pull any air down in there and your back to square one.
yes. Furthest away from ms to closest.
 

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bmboll said:
yes. Furthest away from ms to closest.
Wow.. beats me then. either theres still air in the lines, you got another bad MC, or you have a bad brake.
 

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Their is a difference between 78 and 79 busters they will not work right if you interchange them.
 
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