Hi, again everyone. My question is for an '81 F150. I just got a brand new brake booster and master cylinder, to go with the brand new brake pads, and bled the brakes. Why is the pedal still soft? It has no pressure what so ever.

The first replacement was the booster and the old cylinder leaked pretty much all the fluid, would that maybe have damaged the booster?

DISCLAIMER: Before I get all the "you should let a mechanic/expert do it" replies, this truck cannot run right now anyway because it is missing a part. I just want to know for my own benefit what the possibilities are because, as a girl, I get lied to and scammed. Besides that, I sure as heck don't want to get charged $250 for a $50 job, you know? Thanks for your help!

 

I think I may have heard that you have to bench bleed the brake booster first. Maybe someone else will be able to tell you exactly. Good luck.

-Matt

 

CJSMONNIE; Welcome to the wonderful world of old Ford trucks. I would like to recommend that you pick up a copy of one of the after-market repair manuals like the Haynes or Chilton series. The manuals are a good and inexpensive source of “how to”. If you’re going to have an old truck in your life, you’re going to need one.

My guess is that your master cylinder needs to be bleed to remove any air that may be trapped in the cylinder’s internal chambers. Until all of that trapped air is removed, the brake petal will be extremely soft. The recommended procedure is to bench bleed the cylinder before it is mounted on the truck. The repair manuals will show how that’s done.

I have seen a mechanic bleed the cylinder after it had been mounted. He just barely cracked open the brake bleeder fitting on one of the rear wheel cylinders and then rapidly and repeatedly pumped the brake petal to expel the trapped air. It took about fifty strokes. I’m not a good enough mechanic to know if or not his method is appropriate, but it did work.

In any case, I think you can do the repair yourself and save the cash. I would recommend that if you are the least bit hesitant that the brakes are one hunderd percent, you should have a knowledgeable mechanic check them out. Brakes are just to important to take a chance that they are not in first class repair.

Good Luck – let us know how it all turns out.

 

More than likely you now have air in the lines and the wheel cylinders/calipers and this may be the method you have to use.
But, first, I would use the bleeding package that came with the master cylinder and bleed it free of air first...just to make sure.

Then you will need a helper to do all four wheels (Calipers on the front, and wheel cylinders on the rear). I always like to chock the wheels and start the engine to make the process easier through the booster, but that's just me.
You will then need to "pump up" the pedal until it's stiff or almost stiff. Then the other person will loosen the bleeders until a stream of fluid appears that it free of air. (You can tell when it's free of air when it stops spewing...and the pedal will go all the way to the floor). Leave the pedal depressed until you hear your helper say, "Okay, do it again!" This may take several tries on each wheel before it's clear.

FordF150Fixer's idea about the service manuals is a must.

 

The cylinder only came with brake line adapters. Unless that is the bleeding package?

 

Imagine that?! Everyone I have ever bought came with two plastic hose-to-cylinder adapters and two short tubes for bench bleeding. They also came with a "How To" sheet.
But I always go to Napa or Discount Auto and I have known those guys for years.

Then I guess your only route is the wheel cylinder/caliper bleeding. It will work, just might take a bit longer.

 

Due to my ignorance (and my gender), I go in asking for one thing and they refuse to sell it to me so I walk out with another. As in, "what's the problem?", I tell them and then they say "oh, you don't need (insert the part I came in for), you need (insert the part they push on me)". Hey, I even got conned into buying a $75 battery (excluding $45 core charge and the final $8 they gave me for taking in an old battery). I cannot in complete confidence defend myself so ... I hate going into those places. They always mess with my head. Jerks.

Here, O'Reilly and Auto Zone are closer (only 40 miles away). O'Reilly is where we got the cylinder. The package didn't have any kind of paper inside.

 

Yep, "Jerks"is the word.

Just come in here and let us know next time and we'll help.

Hang in there, I have kith and kin in Lake Jackson who'll go with you if need be.

 

Did you know Autozone has a web site that you can look up parts - get the number of the part and either order it thru the web site and have it delivered to you or go to a Autozone store and give them the number of what you want without the "Parts Boy" telling you what you "Need".

Look on www.autozone.com list your Ford and look up the part you need - there are also pictures of many parts, so you can match it up with what you have.

NAPA & Advance also ofers this service.

I use it alot just to see what's available and cost before I go to the parts store - it gives you an edge.

 

Yes, I love the site (registered last year) but my problem was where I'd have to specify things (133' bed? 10 or 11 brakes?) and part names in order to place my order. I would have to ask all my uncles, some locals, etc. just to find out what I had (bed length, brake size, etc.). Sometimes no one knows. A call to AutoZone is frustrating and they wind up ticking me off. They say to take my truck over and when I get there, they are like, we don't work on them here, we just sell parts. Duh! Not even specifically telling them I am at their website and how do I get the information I need works. I don't remember pictures though - except for on the page of the part you chose.

My uncles just say, "get this part" and give me a Tex-Mex/cowboy name for it. That's all they knew it by. Why my uncles just don't go themselves is beyond me. They go in and come out with what they went in for. 75% of the time I go, I come back with something else and we all wind up angry. I will try Napa's site. They are farther away (60 miles) but if it's less of a hassle ..

 

Yes, you guys have already helped a lot. Where is Lake Jackson? I'd love to have someone go in and just tell them off: no dang it. A fight, a fight. j/k It is less intimidating coming from me though (perhaps it's the high heeled sandals?) Hmm, maybe I should tell them I know karate and will not hesitate to shove a heel up their ... ?

 

Yes I always use the website to look up my parts ahead of time for Autozone, Advance Auto, and NAPA. Then I know what to get and call it when I get there. When I went to Autozone to get the three belts for my truck (air pump, power steering, and alternator) and provided the part numbers; the clerk still gave me three different alternator belts; I asked for a manager at that time.

 

Good for you - the manager should know what's going on with his people.

 

You might try calling the parts store where you got the new master cylinder and telling them that the kit to bleed the master cylinder wasn't including in the box. Maybe they'll give it to you as it should have been included.
I'd recommend bleeding the master cylinder then bleeding the brakes as normal. Should solve your soft petal problem.

My experience has been that the counter people don't know that much(no offense to anyone in this profession) esp. autozone and o'reilly, so I wouldn't take it personally.

Good luck,
Jeff

 

cjsmonnie,

First of all I think you will find that bench bleeding the master cylinder will set you up right. Put the cylinder in a bench vice. When you bought the cylinder it should have come with bleeding tubes (small hoses) that attach where the brake fluid comes out. Put the other end of the tube back into the resevoir, fill the cylinder an start pushing the piston with a large center punch until it quits making bubbles in the resevior. Then put it in your truck and bleed the rest of the system. If your doing it on your own put a jar of brake fluid on the ground and attach a hose to the bleeder one wheel at a time, put the end in the jar of fluid. Keep the level in the jar real low, just make sure the end of the hose is under the surface. Get in and start pumping the brake. On the up stroke the brake fluid will get sucked up the hose, not air. The jar will fill as you put fluid through the system so keep an eye on it.

As far as being a girl and working on trucks forget about it. Most of the parts people you run into know less about mechanicing than you. Any guy that comes along will be more than happy to know you know something about vehicles. And I don't go to mechanics anymore. Around here there are few that are honest and I make less than $57/hr. So it is unaffordable anyway.

You want help? This is the finest forum I have ever seen. Plenty of proffesionals and experienced home mechanics to offer advice and help whenever you need it.

Good luck with your old truck. Don't forget, cussing at hard to remove bolts and parts is REQUIRED while mechanicing, so keep the little ones away!