Im going to put a new master cylinder on my 95 250 this weekend I never did it before but it looks pretty easy,two bolts holding it in 2 brake lines and a wire clip.after I take all that off will it just pull right out?I was told i have to bleed the brakes after i get the new one in but i never did it before.Im pretty sure i know where the bleeder screws are they stick out on top but i tryed turning one and it wont budge.what is the best wrench to use for this?In my book it says turn the bleeder screw one half turn then turn it back and have someone step on the brake and then let it back up.SO I KEEP opeing the bleeder screws up one half turn then i close them and I keep doing this till allthe air bubbles come out on each brake right?where does the fluid come out the top of the bleeder screw or the sides?the problem im having is I cant get the bleeders to open for some reason maybe I was using the wrong wrench or the wrong size im not sure since i never did this before or maybe i was turning it the wrong way?,so i stoped cause the bleeder felt like it was going to snap in half so i came here to get help.any info will help..thanks

 

fordinmudd

If the bleeder screws have not been opened in a while they can be difficult to open and are easy to break. Others here might be able to drill out and correct, if it happened to me I would have to put on a new caliper or wheel cylinder. I would soak them down with PB Blaster or Liquid Wrench, even the day before it you can. I do not know what size yours might be, mine an 8mm wrench fits perfectly. I prefer to use a socket instead of a wrench to loosen but either will work. Mine loosen counter clockwise, tighten clockwise. To bleed loosen about three quarters of a turn and the brake fluid will come out through the nozzle on the bleeder, if coming out the threads tighten it a little. You should attach a clear length of hose to the bleeder screw and run it into a bottle of brake fluid. The method you heard takes two people, one to push the brake pedal, after the other loosens the bleeder screw to allow fluid out, while brake pedal is depressed and bottomed you have to tighten the bleeder screw before releasing This is in my opinion a PITA but if you have patience will work. You repeat this until you have brake fluid with no bubbles in it, might as well flush and bleed until you have all the old fluid out. Keep checking the master cylinder level because if it goes dry you will have to start over. I would spend the $8.00 or so for a one man bleeder. Mine came with the attachments to pre bleed or bench bleed the master cylinder. This makes it a one person job and easier even if you have help. If you bench bleed the master cylinder it will be easier to bleed the brake system. Bleed the master cylinder first, then start with the rear wheel farthest from the MC, then other rear, then front farthest from MC, then other front. Once you have loosened the bleeder screw you will have to use a wrench to tighten before removing the tubing. I put the closed end of the wrench on the hex part of bleeder then the tubing. I am sure others more knowledgable will help if you don't understand my suggestions. There are some Speed Bleeders that have a check valve in them and all you have to do is apply tubing, loosen them, bleed until no bubbles and you are done. You would have to loosen and remove the "stuck" ones though to install.

Scott

 

One main bleeder?that sounds like it would be alot easyer but i dont know what it is or how or where to get one.the truck is a 95 250 4x4 im doing this too,but the front axle is off a 88 f 350 its a dana 60 mono.Someone told me there is a kit I can buy that pulls the brake down while i bleed them making it a one man job where the heck would i get this kit anyway?I will spary the bleeders with pb blaster the day before i do it i could tell the bleeder was going to snap and yes it's been a while last time they were done was in the fall.thanks for the info.

 

I bought my bleeder kit at NAPA auto parts store. It is very simple consisting of a clear length of hose that fits over the bleeder screw. The clear hose attaches securely to a small plastic bottle that collects the brake fluid, the fluid in the line prevents air from entering thus you do not have to tighten the bleeder and loosen repeatedly. You can watch the brake fluid and need to press brake pedal until you no longer see bubbles in the fluid, then tighten bleeder while line is still attached so air cannot re enter the system. When doing a complete flush I wish the resevoir bottle were larger so you may have to empty it a couple of times, don't let it get past full or you will have a mess to clean up. Also keep checking on the master fluid level. I attach, open the bleeder valve, pump brake pedal 10-12 times, then check the bottle, empty if necessary, refill master cylinder as needed, then repeat until no bubbles or clear, then tighten before removing hose. I think the kit to bench bleed the master cylinder was separate.

Scott

 

ok i think ill go buy that kit since im doing the job by myself.thanks for the info you been alot of help..by the way are you really a dentist?..later

 

got the master today funny they dont give you a new reservoir so ill guess ill just use the old one its seems to be ok.i got a rebuilt one ran me $45.00 get 10 back for the core.now i have to figure how to bench bleed the master this should be fun.

 

fordinmudd,

I hesitated when I registered with Ford Truck Enthuiasts to utilize that user name because I am well aware that many people do not like dentists. I graduated 1981 DDS, practice in Boulder, Colorado about twelve blocks from the foothills of the Rocky Mountains. I drive a 1989 Ford Ranger that I bought from my father. Something I have learned from these forums is that intelligence and ability is not limited to a person's education. While I daily tackle molar root canals, impacted wisdom teeth etc. am humbled by the knowledge and ability of this forum's members. It is sometimes frustrating to know I can remove a wisdom tooth bony impaction, yet experience great difficulty completing service or repair that is routine for most contributors to this forum. I think perhaps that in diagnosis dentistry and medicine are more simple than automobiles and trucks. People are basically the same while there are numerous makes and models of vehicles. If you asked out of curiosity you have your answer. I have learned much with the generosity and help of others, was trying to return the favor. If you have questions about dentistry I would be happy to help, though am not sure this forum is the proper place?

Scott

 

no problem .i have no problem with dentists i was just wondering thats all.....my next question is how do i bench bleed my new master?do i put it on the truck when i do this or do i really do this on a bench?also how do I get the old reservoir outto put it on the new master?In my directions it says to transfer any parts to the new master what parts would this be?as far as i can tell its just the reservoir there is no parts inside this master i have to transfer from the old one is there?sorry for all the question but the directions are very vague.thanks!

 

Hi fordinmudd,

I read through both of the after market manuals for my Ranger and if your truck is 1986 or newer it has the master cylinder with the white plastic reservoir. They show an illustration of just carefully prying it off the metal portion below. It inserts into two areas so pry carefully from the middle and underside. Transfer it to your new MC. You can actually bleed it on the bench in a vise to secure it. Did the master cylinder come with plugs in the holes which connect to the brake lines? If not you need to insert the proper sized plugs and tighten. Then fill the MC with brake fluid. Remove the back plug first, then use a Phillips screwdriver to push from the rear which substitues for the brake pedal, since it does not involve high pressure, place your finger over the hole before releasing pressure on the screwdriver which seals and prevents air from being drawn back into the master cylinder. Repeat this and when you depress the screwdriver it will force your finger off the hole allowing air inside to be expelled. When only brake fluid and no air is being expelled install the plug and do the front port the same way. I had a kit and you installed screws while MC was on vehicle and they had a piece of tubing that looped from the port into the master cylinder fluid. You then bled each port until no more air or bubbles, using brake pedal while on vehicle instead of screwdriver on the bench with vise. I am not sure, but if you do not want to bench bleed you may be able to install the MC and then fill with fluid and if you have the time and patience bleed until no more air. I am somewhat shaky on the issue of anti lock brakes and if you have anti lock brakes I would pre bleed MC. I am sorry, would be simple to observe and help, much more difficult to describe.

Scott

 

Ok I did get two plugs and a little round gasket with my master.On the back of the master there is a lock ring should I take that off to bleed it?I cant seem to get any plug to fit the back so im guessing maybe I take it off?

 

The openings that you plug are actually on the side of the MC where the brake lines attach of which there are two. The instructions said to open the "back" one first, meaning the most posterior on the side. I am not familiar with the locking ring you describe but it is probably for shipping and I would guess you have to remove it for bleeding and installation. The back of the MC would be where you have to use a screwdriver to apply pressure.

Scott

 

Besides the reservoir to transfer there is another part to transfer to the new master?where the rear brake line goes in there is some sort of part sticking out and i notice the new one doesnt have it.what is that anyway?should i have gotting that with the new master or no?

 

That other part you have to use from the old one is called a proportioning valve.

 

do not remove snap ring

 

ok then the snap ring stays on?thanks........what if i dont bench bleed the new master cylinder what is the worst thing that would happen?more air in the lines?