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I have a tangential brake related question. My 2002 has 215,000 miles. Is driven very intermittently. I have had it for 5 years and have never bled the brakes.
The brake pedal went to the floor the other day so I assume I have bad master cylinder (since I have no leakage anywhere).
Do you think I should change the hydroboost along with MC while Im changing the master cylinder? The truck is 16 years old...I hate doing things twice.
Hold on the boost. Take the ports off the MC and plug them. Dirt cheap, you probably have them from a previous job. MC full. See if your peddle collapses. If you've got steering and no brakes, your starting right there.I just replaced mine.
Make sure if you do get a new MC it crosses over to ford for the correct year. I chased my tail for a year with poor mileage and burned calipers as well as countless brake pads.
Sold me a 2009 vs 1999 MC,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Brakes were always on.
A bad steering pump can cause a hard pedal, but won't cause the pedal to go to the floor.
If the pedal is dropping without any external leaks you likely have a bad master. The ABS valves can do this too, but it's less common. I wouldn't bother with the booster. I think you can replace the booster without disconnecting the tubes from the master, if so, replacing it later if it becomes a problem won't be much harder than doing it now.
Quick tips to master replacement: First thing is to put rags under the master to catch any drips/spills and have a garden hose or water containers ready. Be careful as you remove the master to not drip fluid onto the fender or any other paint you care about. If it gets on paint flush thoroughly with water, don't try to rub it off with a rag.
Install the new one dry, bolt it up tight but only finger tighten the lines on. It's often easier to get the flare nuts on the lines started before tightening the cylinder on so you can wiggle it around. Before bleeding the master it needs to be level or with the front a little lower than the back. If the front is the higher it can create an air trap in the cylinder. I usually park it as needed before starting the work, sometimes using wood blocks or ramps. Or you can park on a hill or jack the back end up if needed. Fill the reservoir and wait for it to start dripping from the lines then tighten them. Short pumps on the pedal, 1-2 inches, till all the air is out and the pedal is firm. It'll take a while. Then several firm pumps to assure it's air-free. I start the engine to get the booster working and make good pressure, but not totally necessary. Since your system is in need of bleeding, open the bleeders and it'll gravity bleed the old fluid out, don't let the reservoir run down letting air into the cylinder. I put a short piece of hose on the bleed nipples so I can direct the fluid into a container. This also lets me pump the pedal with the bleeder open without sucking air into the calipers/wheel cylinders which is faster and more effective than just gravity bleeding. Some fluid will usually seep out around the bleeder threads, but shouldn't make much mess. Rinse off any fluid drips & take a drive.
Hold on the boost. Take the ports off the MC and plug them. Dirt cheap, you probably have them from a previous job. MC full. See if your peddle collapses. If you've got steering and no brakes, your starting right there.I just replaced mine.
Make sure if you do get a new MC it crosses over to ford for the correct year. I chased my tail for a year with poor mileage and burned calipers as well as countless brake pads.
Sold me a 2009 vs 1999 MC,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,Brakes were always on.
Denny
Denny, I'm a little confused on your instructions.
RockAuto has quite a few options for master cylinders. I know I need to chose the one with cruise control. Other than the some saying -Bore Size=1-3/8"-/, they all seem the same in the pictures.
A bad steering pump can cause a hard pedal, but won't cause the pedal to go to the floor.
If the pedal is dropping without any external leaks you likely have a bad master. The ABS valves can do this too, but it's less common. I wouldn't bother with the booster. I think you can replace the booster without disconnecting the tubes from the master, if so, replacing it later if it becomes a problem won't be much harder than doing it now.
Quick tips to master replacement: First thing is to put rags under the master to catch any drips/spills and have a garden hose or water containers ready. Be careful as you remove the master to not drip fluid onto the fender or any other paint you care about. If it gets on paint flush thoroughly with water, don't try to rub it off with a rag.
Install the new one dry, bolt it up tight but only finger tighten the lines on. It's often easier to get the flare nuts on the lines started before tightening the cylinder on so you can wiggle it around. Before bleeding the master it needs to be level or with the front a little lower than the back. If the front is the higher it can create an air trap in the cylinder. I usually park it as needed before starting the work, sometimes using wood blocks or ramps. Or you can park on a hill or jack the back end up if needed. Fill the reservoir and wait for it to start dripping from the lines then tighten them. Short pumps on the pedal, 1-2 inches, till all the air is out and the pedal is firm. It'll take a while. Then several firm pumps to assure it's air-free. I start the engine to get the booster working and make good pressure, but not totally necessary. Since your system is in need of bleeding, open the bleeders and it'll gravity bleed the old fluid out, don't let the reservoir run down letting air into the cylinder. I put a short piece of hose on the bleed nipples so I can direct the fluid into a container. This also lets me pump the pedal with the bleeder open without sucking air into the calipers/wheel cylinders which is faster and more effective than just gravity bleeding. Some fluid will usually seep out around the bleeder threads, but shouldn't make much mess. Rinse off any fluid drips & take a drive.
Thanks so much for your help! I haven't had a chance to get under the truck as of yet but I looked at the brake fluid reservoir and it was empty yesterday so I must have blown a seal in a caliper. But since I need to bleed the system anyway, I'm gonna buy a new master cylinder. Its time, at 215000 miles. I need to be able to trust the truck. Hence my question about the hydroboost. I bought the truck 4 years ago and honestly, I think the brakes are terrible, but I dont have another f350 to compare them to.
As it stands there is no way I could lock up my fronts in a panic stop. Maybe bleeding the system will give me better stopping. Maybe not. Hence my question about the hydroboost perhaps being weak.
If the hydroboost unit replacement doesnt require rebleeding the brakes, Im willing to wait. Otherwise I prefer to change the MC, hydroboost and bleed all at once (plus replacing whatever is leaking).
I second what 88 said, however, my buddys' conclusion WAS the ABS unit. We got a used 1 from junkyard with the last 2 letters being off then that of his original. Junkyard came from an Ex but had all the same ports..etc. It fixed the pedal but was setting the hard code(will post thread)..His initial problem was pedal going to floor slooowwwly while at stoplight/sign but still worked while motoring...3 hydroboost, 1 power steering pump and 4 master cylinders later, problem still existed..Removed junkyard ABS, installed original and code was gone, but pedal still dumped...had one shipped from backeast(abs with correct numbers) and alls good.
I second what 88 said, however, my buddys' conclusion WAS the ABS unit. We got a used 1 from junkyard with the last 2 letters being off then that of his original. Junkyard came from an Ex but had all the same ports..etc. It fixed the pedal but was setting the hard code(will post thread)..His initial problem was pedal going to floor slooowwwly while at stoplight/sign but still worked while motoring...3 hydroboost, 1 power steering pump and 4 master cylinders later, problem still existed..Removed junkyard ABS, installed original and code was gone, but pedal still dumped...had one shipped from backeast(abs with correct numbers) and alls good.
Sounds like a nightmare! Luckily for me, right now, I have a burst somewhere in the system. I just need to find a minute to get under the old truck.
I found the cause of my brake failure. A rusted and perforated hardline running along the the frame to the rear brakes right behind the fuel tank. Ive had bad luck cutting and flaring my own lines in the past so Id rather spend the extra on a Ford part or aftemarket pre-cut and bent section.
I wouldn't be surprised if you were unable to obtain preformed brake lines and have to bend your own or get flexible line and put it in. Mine has been replaced down the driver's side by the PO but I didn't pay attention as to which method they used. The only reason I even noticed it is because the old line is still there and it got my attention when I was under there poking around.
I wouldn't be surprised if you were unable to obtain preformed brake lines and have to bend your own or get flexible line and put it in. Mine has been replaced down the driver's side by the PO but I didn't pay attention as to which method they used. The only reason I even noticed it is because the old line is still there and it got my attention when I was under there poking around.
Anyway, here's a bump for you.
Thanks my friend.
One of the benefits of having one of the most popular vehicles on the road is that at least two companies sell entire stainless steel breakline kits. DORMAN and IN LINE TUBE.
10-17-2018, 11:00 AM
