Community Forums

firedogg · 02-21-2016, 12:26 AM

Hey gang --

Was trying to do some trip prep on my 1994 Thor Residency 35' class A. I noticed, out of no where, that I was leaking brake fluid, and at a first inspection, it seemed to be coming from between the reservior and the master brake cylinder. I could see a small amount leaking and when i tried to 'wiggle' the reservoir, i could see it move and some small air bubbles. SO, I figure on replacing the master cylinder.

That being said...is there anything specific I should know about changing this on the for F53 chassis? Mine is located what looks like off the frame off the drivers side behind the front wheel. I've changed master cylinder's before...and I have the cylinder replacement...but anything special or unique about this challenge, other than it's kindof a pain to get to since I have to jack it up and remove the front wheel?

Thanks in advance for your helpful hints and replies! Cheers!

Mike

**JohnRR** · 02-21-2016, 02:29 AM

Don't forget either jack stands or cribbing while your working under it.

Nick-B · 02-21-2016, 09:58 AM

Master cylinder replacement is straightforward and removing the tire to get in there is the right way. It shouldn't be any surprise that the brake components are starting to fail after 22 years. If the rest of the system is original or of unknown age, now would be a good time to freshen all components. Calipers, pads and rubber hoses will all age out regardless of miles driven.

firedogg · 02-21-2016, 02:44 PM

Quote:

Originally Posted by Nick-B

Master cylinder replacement is straightforward and removing the tire to get in there is the right way. It shouldn't be any surprise that the brake components are starting to fail after 22 years. If the rest of the system is original or of unknown age, now would be a good time to freshen all components. Calipers, pads and rubber hoses will all age out regardless of miles driven.

Hey Nick --

I agree. I've changed pads and such, not the hoses. Just noticed the leak the other day, must have just started so wanted to get a jump on it before it became a performance problem. I'm big on preventative maintenance -- just wanted to see if there was anything I was missing in terms of specifics related to this master cylinder.

My assumption (or hope) is its just a bolt in / bolt out, bleed brakes and put into service just like any other rig...is that assumption correct? I have to take a closer look, but I did notice a "brake booster" I think I saw that came off the side of the cylinder. I'll snap some pics tomorrow.

leesdx1 · 02-21-2016, 10:30 PM

Quote:

Originally Posted by Nick-B

Master cylinder replacement is straightforward and removing the tire to get in there is the right way. It shouldn't be any surprise that the brake components are starting to fail after 22 years. If the rest of the system is original or of unknown age, now would be a good time to freshen all components. Calipers, pads and rubber hoses will all age out regardless of miles driven.

Changed the MC and pretty much straightforward. 2 bolts holding the MC to Booster, 2 bolt holding bracket and undo 2 lines on my Chevy. I also changed all 5 rubber hoses since you have to bleed the brake system.

firedogg: Did you have any trouble finding the right MC for your RV? As for me, I ran the VIN# and got the workhorse P/N but still the wrong MC. Finally a good part guy knew about Automotive and the 3rd try hit the nail.

firedogg · 02-21-2016, 11:12 PM

Quote:

Originally Posted by leesdx1

Changed the MC and pretty much straightforward. 2 bolts holding the MC to Booster, 2 bolt holding bracket and undo 2 lines on my Chevy. I also changed all 5 rubber hoses since you have to bleed the brake system.

firedogg: Did you have any trouble finding the right MC for your RV? As for me, I ran the VIN# and got the workhorse P/N but still the wrong MC. Finally a good part guy knew about Automotive and the 3rd try hit the nail.

well I haven't pulled the MC yet, but I didn't have any trouble finding it so to speak. Had them look it up by a 1994 Ford F53 Motorhome chassis, came right up. guess pulling it out and comparing will tell the true tale. Hoping to find out tomorrow

Nick-B · 02-22-2016, 02:09 PM

The brake booster should be hydraulic and pressurized by the power steering pump.
If memory serves correctly, just 2 nuts and the 2 brake lines to replace the MC. Oh yeah, and the brake pressure switch too. There was a recall on that switch as the originals could leak and spit brake fluid on the exhaust = fire! I bought the updated replacement off Amazon and installed it myself when I did the MC.

firedogg · 02-22-2016, 04:14 PM

Quote:

Originally Posted by Nick-B

The brake booster should be hydraulic and pressurized by the power steering pump.
If memory serves correctly, just 2 nuts and the 2 brake lines to replace the MC. Oh yeah, and the brake pressure switch too. There was a recall on that switch as the originals could leak and spit brake fluid on the exhaust = fire! I bought the updated replacement off Amazon and installed it myself when I did the MC.

Uh...well that's un-nerving. Any chance you remember the part # or have an old order of what you replaced and what with? That's a terrible thought, and since I'm owner #3, I have no idea whether that's been changed or what to look for.

Id like to order one of those up....

twinboat · 02-22-2016, 04:58 PM

The recall for the cruise control switch was a fused harness. They did not change the switch.

The "recall harness" has 2, 2 amp ato fuses, in little covered holders.

One was on the incoming wire and the other on the outgoing wire.

If it is there, you will see it. It should have a big warning tag on it.

It wasn't that it leaked brake fluid on the exhaust, it would short internally and burn the un-fussed wires to it, starting a fire.

If you change the switch do not remove the harness.

Google Ford Cruise Control recall, it will explain it all.

The switch is sold at many auto parts stores for $20 to $25.

CCS1 should be the part #

kysportsman · 02-22-2016, 06:18 PM

Here is the one I installed in my 1997 f53 I think they are the same. On the recall that was on these they would unplug the connector from the switch and check for any signs it had leaked. If it had not leaked they would install the fused wiring harness. But if it had leaked they would replace the switch with this updated kit which includes the switch and adapter harness because the plugs are a different size on the switches. You can look up to see if the recall has been done or not. I could tell by looking at mine it had not been done as there were no extra harness in between the wiring to the switch. Amazon.com: Motorcraft SW-6350 Brake Repair Kit: Automotive

Motorcraft sw-6350 brake repair switch. this is the part # if the link above dont work.

subford · 02-23-2016, 08:30 AM

Images:

The recall harness:

/

Nick-B · 02-23-2016, 01:47 PM

The original recall called for the fused harness as a "band-aid" fix. The problem was the switches would leak and brake fluid is flammable. Here is a quote from autosafety.org concerning the Ford recall.
"The switches, which run continuously even when the vehicle is not in operation, are prone to fail over time and cause electrical fires. One side of the switch is electrical and the other side is flammable hydraulic fluid, a combination conducive to fire. Fires in these vehicles have caused numerous house and garage fires, and resulted in deaths in several states."

The best fix is both a new switch and harness.

My switch actually screws into the master cylinder body. If yours is like Subford's then it may be a different part so I hesitate to give a part number - IF I can find record of it. James' Amazon part reference might be correct.

cbilodeau · 03-01-2016, 03:06 AM

The leak could also be the result of brake oil boiling. If you did not change the brake oil in the last two years, it did accumulate water which is subject to boiling. This will cause a spillage at the Master Cylinder cap.

Old brake rubber hoses will breath more water so it is a good idea to changed them.

The new F53 recommends Super DOT4 instead of DOT3 oil. Super DOT4 has a higher boiling point. I changed my Master Cylinder, rubber brakes hoses and did put Super DOT4. Racers motorcycle use Super DOT4 also so a motorcycle shop will have this oil.

There is a difference between Super DOT4 and DOT4 so look for "Super DOT 4" label. If you can not find Super DOT4 then use DOT4 or DOT5.1. Some DOT4 bottle will say High DOT4 to make you think it is "Super DOT 4" but it is simple DOT4. So the word "SUPER" is important.

Also, don't put DOT5 oil, since it can not be put over your existing oil and is more complex to use because it is silicone base. (DOT 5.1 is a good alternative to DOT5 and can be put over your existing oil)

firedogg · 03-03-2016, 12:05 PM

Quote:

Originally Posted by cbilodeau

The leak could also be the result of brake oil boiling. If you did not change the brake oil in the last two years, it did accumulate water which is subject to boiling. This will cause a spillage at the Master Cylinder cap.

Old brake rubber hoses will breath more water so it is a good idea to changed them.

The new F53 recommends Super DOT4 instead of DOT3 oil. Super DOT4 has a higher boiling point. I changed my Master Cylinder, rubber brakes hoses and did put Super DOT4. Racers motorcycle use Super DOT4 also so a motorcycle shop will have this oil.

There is a difference between Super DOT4 and DOT4 so look for "Super DOT 4" label. If you can not find Super DOT4 then use DOT4 or DOT5.1. Some DOT4 bottle will say High DOT4 to make you think it is "Super DOT 4" but it is simple DOT4. So the word "SUPER" is important.

Also, don't put DOT5 oil, since it can not be put over your existing oil and is more complex to use because it is silicone base. (DOT 5.1 is a good alternative to DOT5 and can be put over your existing oil)

SUPER GOOD INFO!!

It hasn't been driven lately, so it wouldn't be because of brake boil in my particular case. BUT, i had been working on and replaced all 4 sets of pads on all the brakes. Could I have forced some back out the top by squishing the calipers open when I was re-installing? Didn't seem likely to me, but after only moving it enough to do some servicing, and having it be a new issue, I figured it had to be related to the work I had done? I cleaned it up, and am thinking now about waiting a bit, take it for a test drive, see if I have any other issue before replacing the whole MC....thoughts?