Master Cylinder Upgrade Part Numbers
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Master Cylinder Upgrade Part Numbers
 
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This post was updated on .
Working on a brake repair/upgrade for my 1984 using a later model (Bricknose/Aeronose) master cylinder. Right now I'm getting my butt kicked when it comes to brake bleeding (Long story short: Vacuum bleeders suck, waiting on a pressure bleeder to come in). In the mean time though, I do have some information to share.
First off, Raybestos makes a new master cylinder for the later application that includes the residual pressure valve, the reservoir, and the reservoir level sensor, specifically MC39634:  As of this writing RockAuto has them for $33 before tax and shipping (no core)... which pending testing, is a great deal. One thing I plan to (eventually) do is wire the reservoir level sensor into the brake warning circuit (parallel to the existing proportioning valve switch). The connector to do this is Motorcraft WPT-446; I de-pinned the center terminal (which on my pigtail was double wired) and used the outer two pins. The third pin is tied to one of the outer pins; this is used on later model vehicles to tell the ABS controller if some twit has unplugged the sensor to bypass a low level condition (which the ABS controller needs to know about; activating ABS with a brake line failure is a great way to make a bad situation worse!). Before going this route, I didn't know the Raybestos MCs came with all the trimmings (RockAuto's pictures showed there not being a residual pressure valve) so I opted for a used eBay Ford unit... which was a complete loss. Nothing worked... it was seized on arrival and the front brake circuit wouldn't bench bleed. Also, the reservoir sensor was toast... more on that below. If one needs to replace one of these reservoir sensors: you'll read online the only fix is to replace the entire MC (or the reservoir at least). Not technically true, as there are two options: 1. Find an NOS sensor. It's Motorcraft E6DZ-2L414-A, usually found on ebay for around $70 (way more expensive than a Raybestos MC with a new sensor, but if you're a purist dead set on a new sensor, that's the way you'd need to go) 2. Rebuild the sensor. The sensor is merely a potted reed switch; through some hacking away, I was able to dissect my faulty sensor (which seemed to have a bad solder joint, but I broke the switch tube):   A better way to do this may be to boil the sensor in a pot of water; the potting compound loses it's adhesion and softens with just a little heat, which would probably allow one to yank the tray out of the tube and pick off the compound without cutting or scorching anything. I made the mistake of using a MAPP torch on mine to soften the compound... even lightly used, it melted the plastic tray. The switch tube I used to repair mine is a 14mmx2mm 0.55A unit:  If I were to use this switch, I'd pot it with some hot glue... but since I have a new one (that works great), I'll use that instead! Master cylinder installed (I had to ditch the line bracket and re-bend the lines as the front and rear brake circuit positions are switched):  Now if I can get the darn things to bleed...
1984 F150: 300 L6, AOD, RWD. EEC IV / TFI, Feedback Carter YFA Carb. Stock everything but radio (for now).
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Re: Master Cylinder Upgrade Part Numbers
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Thanks for the info, Larry!
 And when the pressure bleeder gets in you'll be amazed at how easy it is to bleed brakes with the new master cylinder.
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Re: Master Cylinder Upgrade Part Numbers
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I had an attractive helper when I did Darth's.
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
Re: Master Cylinder Upgrade Part Numbers
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Yes, you did!
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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This post was updated on .
In reply to this post by ratdude747
Updates!
First, According to RockAuto pictures, Motorcraft BRMC63 is also a new complete MC with all the trimmings. $69 per... if the Raybestos one ends up being a fail, that'll be my plan C (as I'm already on plan B!). Second, the pressure bleeder came in... worked great. Used the HF vacuum bleeder for a catch bottle... also worked great (if not overkill  )
I now have a working brake pedal... but sadly no better than the old one I removed. Guess it wasn't faulty... and my brakes just suck a bit (then again, I'm comparing it to a lighter newer 1995 ranger with dual piston (stock!) calipers  )
I also was able to wire in the level switch. Originally I was planning to splice it near the Proportioning valve switch, but due to access issues I only got far enough to cut back some of the harness tape. Better idea: Turns out the needed connections (Brake Warning light: Pink/White; Ground: Black) are in an exposed section of harness right below the brake booster, allowing for a location to splice into:   Throughout the process I did several electrical tests to confirm I had the correct wires, culminating in a "shove the float and see the light" test that passed with flying colors. All assembled (now this morning):  Sadly I must have had a leak or spill I wasn't aware of... bye bye paint on the bottom of the brake booster  :
 Not sure how to fix that. I'd prefer not to pull it again... and all I have is spray primer and paint (and painting it in place isn't practical for hopefully obvious reasons). Can't be much worse than it's unpainted form? Yeah, I suck at anything paint and body related.  Would I do this again? Only if I blew a master cylinder... which I though I did, so it's a yes?
1984 F150: 300 L6, AOD, RWD. EEC IV / TFI, Feedback Carter YFA Carb. Stock everything but radio (for now).
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Re: Master Cylinder Upgrade Part Numbers
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Administrator
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Good job, Larry! (In spite of the spill.)
 Thanks for documenting it, including the part numbers, as others are sure to want to follow in your steps.
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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In reply to this post by ratdude747
The good news: I found the source of the spilled brake fluid... And doubly confirmed that the reservoir switch works.
The bad news: the good news is because my rear brake line didn't seat/seal right and was barfing fluid everywhere!  I also was away from home... So I limped to the local Menards and got a wrench and fluid. Thankfully it seems that loosening and retightening the fitting did the trick.
1984 F150: 300 L6, AOD, RWD. EEC IV / TFI, Feedback Carter YFA Carb. Stock everything but radio (for now).
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I think the good news easily outweighs the bad news. Congrat's!
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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I still need to drive home yet...
 So no jinxing!  The pedal feel did improve after fixing the leak... so maybe the old MC was indeed dead? Hard to say... On the plus side, the switch alerted me to the issue before the MC ran dry (still had 1/4 a tank of fluid). Which is way better than the old setup which seems to be more of a "you lost your brakes, prepare to die!" light. When I bought the truck the rear brakes were dry (due to a bad MC) and the warning light wasn't lit. Not a very effective setup?
1984 F150: 300 L6, AOD, RWD. EEC IV / TFI, Feedback Carter YFA Carb. Stock everything but radio (for now).
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I don't think mine has a float, but can you show a pic of that?
And glad you made it home and have no leaks.
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Assuming you mean the 1999-2004 F450 Super Duty (which is the oldest F450 I'm seeing on RA), it's a bit different. And the level switch has a different connector.
Here's the RA picture of one (Wagner, what I could find that shows the connector):  From what I am seeing, All Bricknose and Aeronose MC's used the same reservoir; there were a few versions used (likely differing in bore size more than anything) but the reservoir was the same. EDIT- Looked at the 2005 F450, those MC's indeed have no level switch... maybe that's what you have?
1984 F150: 300 L6, AOD, RWD. EEC IV / TFI, Feedback Carter YFA Carb. Stock everything but radio (for now).
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Re: Master Cylinder Upgrade Part Numbers
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