Master Cylinder... Which one

[frankcal]

So I am need of a new master cylinder and have a question on which one to purchase from rockauto because they have 2 that I'm interested in but want to know exactly which one before I make the purchase because I've already bought expensive wrong parts before. The two cylinders I'm looking at are motorcraft ones and I just wanna stick with stock on this one.
First: MOTORCRAFT Part # BRMC162 w/ Speed Control at $72.99
Second: MOTORCRAFT Part # BRMC47 w/o Speed Control at $113.99

I'm really not sure at all what it means by with or w/o speed control so if you guys can explain. Also if you have any sugguestions on how to do the whole process. For example on how to bench bleed the cylinder and if I would have to bleed all of the brake lines or not. The reason why I'm replacing it is because their is a good amount of stainage on my brake booster where the master connects to. Also the real reason why I'm actually doing it now is that yesterday when I came out of the store my car was kinda hesitant to start and would kinda putter and buck in the parking lot and on my drive home that was about a mile from home. Once I got home I checked the car and there was grayish smoke coming from the exhaust and a foul odor as well as black soot coming from the exhaust. After reading up on it looks like it could be that there is a leak in the vaccuum hose and brake fluid is getting in. So last night I just put some seafoam in my gas tank since I had just filled up and the car drove fine but still had a little bit of smoking and soot coming from it. This morning I cleaned the MAF sensor and IAC valve just to see if it would help and I had been planning on doing this anyways. It really didn't make that much of a change other than it would pick up speed a bit faster. But nonetheless I am still getting a very small amount of black soot from the exhaust everytime I turn on the car and there seems to be a lot more condensation then there ever was before. So hopefully you guys can help me out on this one so I don't end up ruining my car or worse crashing so I greatly appreciate any help I can get from you guys. My car is a 2003 explorer sport 2wd with about 89k on the odometer.

 

[frankcal]

I forgot the pics of the exhaust to show what it is that I'm ecountering.

This is the car at regular idle early in the morning:

This is what happened after I revved the engine:

Like I said now it is only about a drop or two of this soot when first warming up. The car is driving normally and no check engine light at all. The brakes are also fine on the car they are not spongy at all and I have had this stainage on the brake booster for some time now maybe about 5 or 6 months that I've noticed. Maybe I should lean towards another issue but not really sure. I did fill up the gas tank yesterday but had driven about 20 miles after fill up before I went into the store and encountered this problem. Could it just be a bad tank of gas? I filled up yesterday with sam's club gas since it was cheaper than what I usually put which is chevron.

 

[kdspapa]

Speed Control means Cruise Control. If your truck has cruise control you want the master cylinder with the wire connector to it. Change the master cylinder and see if that helps stop the smoking. You will probably have to clean up the vacuum hose. Good Luck!

 

[Vic_Ferrari2002]

I would have to think that the with or w/o speed control is referring to 1 of 2 things, either the cruise control or the traction control. After looking on VatoZone's website I am leaning toward the traction control. As far as the brake fluid getting into the vacuum tube, are you loosing brake fluid? Secondly as far as the bench bleeding goes I would definitely suggest you bleed all the brakes starting with the furthest from the m/c and working to the closest. I have found it is always a good idea to flush your brake system every few years with a good quality brake fluid as it does somehow seem to accumulate moisture in the lines.

Hope this helps.

 

[frankcal]

Thanks for the help, I do have cruise control but it actually hasn't been working lately the light just flashes on the dash but doesn't actually engage. I've only needed the cruise control once on a trip to san francisco and it worked fine that time even though it didn't work before that. Could the cruise control be affected by a bad MC? I'm going to get the one with the Speed Control and hopefully it fixes that cruise control issue but seems weird to me that it would be cheaper than one w/o it. Guess it works out for me.

 

[frankcal]

I am loosing brake fluid from the cylinder but its still kinda close to the fill line, maybe about half way through the "m" on the MAX fill lettering. I cleaned the brake booster off this morning and after driving it around town locally for about 30 miles in total there was staining again on the brake booster where the master cylinder goes connected to it. How exactly would I bleed the brakes? Sorry for the dumb questions I've just started working on my car myself and barely getting to know it. Would I need any special tools or it pretty straight forward. Thank for the reply

 

[kdspapa]

I purchased a MityVac vacuum pump to blead my brakes. It's a good tool to have. I think I read you can pour some Seafoam down the brake booster vacuum line to clean it out. I'm not sure what you have to do to clean out the booster though.

 

[frankcal]

Thanks I'll look into that vac. I have done the seafoam on the brake booster and I'm not sure if it cleaned out the booster or not but it did help me with gas mileage though

 

[Chikar]

Before you spend a lot of money on a master cylinder you may not need give this a try.

While somebody is in the truck, engine running, keep a close eye on the master cylinder area while they repeatedly step on the brakes. You'll be looking for brake fluid seepage which may be getting blown back onto the brake booster by the air flow from the fan. This isn't a great test without the truck moving and more air flowing but hopefully you'll see where the fluid is coming from.

If the brakes are firm, not spongy, I think you'll be wasting your money on a new master cylinder without determining exactly what the problem is.

Black soot from the exhaust, grayish exhaust smoke, puttering and bucking, a foul odor, etc sounds like an engine that's running too rich.

 

[frankcal]

Thanks for the suggestions Chikar, so when I do this test and see exactly were its leaking from what then? I mean like if I see it leaking from the MC then that means I should replace it right?
Also if the engine is running too rich what can I do to pinpoint the problem? Could it just be a bad oxygen sensor or something else thats easy to fix? The smoke was kinda gray at first but then turned white and now there really isn't any smoke just a drop or two of soot in warmup idle.

 

[Chikar]

Well, the master cylinder itself isn't going to leak brake fluid unless the cylinder body is cracked and that's very unlikely.

It's more likely to be a leaking brake line connection or a leak at the cruise control deactivation switch on the forward end of the cylinder. It could even be a crack in the fluid tank on the top of the cylinder. I'd think if a brake line connection was leaking there would be air in the lines and the brakes would feel spongy.

The key thing is to find out where the fluid is coming from and let us know.

That deactivation switch, by the way, is a very likely cause of your cruise control just flashing the light on the dash when you try to engage cruise. They've a history of going bad.

At this point I think we should concentrate on one problem at a time. Brakes are a critical safety issue so let's make sure they're OK first then move on to the exhaust issue.

 

[rickybobby]

Chikar, it is extremely common for master cylinders to leak internally into the brake booster. the staining the OP is describing is a very definitive diagnosis of a leaking master cylinder. I do agree that the master cylinder is very unlikely to be causing the engine problems

 

[Chikar]

Thanks Rickybobby;

I have found master cylinders leaking into the brake booster but haven't yet seen one leaving visible evidence on the outside of the booster.

Thanks for the tip, it's always good to get more knowledge.

Back to frankcal.

Please keep a close eye on fluid level in your master cylinder resevoir. If you see it dropping you do have a leak somewhere. Based on your description and rickybobby's tip you may have to replace the master cylinder.

If you determine you are losing fluid forum members can advise which master cylinder you need.

 

[frankcal]

So I just finished doing the test that Chikar suggested and couldn't find any leak anywhere. I was there for about 30 minutes braking while parked and also reversing and pulling forward about 20 feet in my driveway continuously and couldn't find any leak anywhere. So I just cleaned up the master cylinder really good as well as the brake booster and will go out for a drive and see if I can determine where the leak is. If it does happen to be that the master cylinder is leaking where it connects to the booster could be something as simple as a bad seal or would the whole thing have to be replaced. I will keep an eye on my fluid though, I marked it off with a crayon to tell exactly where its at.

 

[frankcal]

So after driving around yesterday I came back home and notice the leak again. The only place that it is leaking from is where the master cylinder goes connected to the brake booster. There was a bit of leakage maybe about 4 or 5 drops that stained the brake booster again. So I will have to buy a new master cylinder to replace it but I think the ones I listed above are for the wrong year. I believe the one I need is MOTORCRAFT BRMC3 which is about 160 so I'll buy that next week. Anybody recommend any other good replacement master cylinders that are somewhat cheaper? If not then I will buy the motorcraft and not skimp out on safety

Anybody have any input on what can be causing the black soot. My spark plug wires look kinda burnt on number 4 and 5 so I bought a new motorcraft set as well since they have never been changed even though I changed the spark plugs about 4k miles ago. Other then the spark plug wires everything else seems fine in the engine and cables. The black soot is steadily decreasing but I still get about 1 or 2 drops in warmup. And the car is continuing to run perfectly fine, no stalling or rough idle

 

[kdspapa]

I read on another thread about putting Seafoam into the brake booster that it only injects the Seafoam into a few cylinders. If you're sucking brake fluid through you're booster hose than you're getting it sucked into a few cylinders as well. I don't remember which cylinders are effected but once you change your master cylinder, the other problem may clear-up too.

 

[my98nnj]

Condensation is a by-product of combustion. As is get cooler you'll see more condensation as the engine warms up. It will spit out your tail pipe as well as the weep hole in your muffler. It's normal. The fact that its a little dirty may indicate your running slightly rich. When was the last tune up done?

 

[frankcal]

@kdspapa: yeah thats what I'm hoping it is and not some other costly repair.
@my98nnj: I understand the whole condensation part about when it gets colder but my issues with the condensation were happening when we were actually having record breaking heat this weekend. It just started getting cold last night actually so I know its not because of the weather but something else that is triggering all that. The last time I had a tune up was about 4k ago which included: oil change, change the spark plugs, flush the coolant as well as replace the pcv valve because it had cracked. This weekend I am going to change the spark plug cables and the fuel filter not sure what I else I can do that will help. But now I'm only getting the black soot every other time I start up the car so I'm hoping it was just a bad tank of gas and its all burning through now since I'm at about 1/4 left on that tank.