Hey, all, the 81 300D is losing brake fluid from the rear (closest to the firewall) section of the brake fluid reservoir. Warmed it up and took it for a short spin yesterday for the wife, and the pedal was super soft. Put all the fluid I had in it at the gas station, and drove it home. Where's the first place to look, in this case. It's been fine up till now. Had the brake pads replaced about 3 months ago. Thanks for the input. I'll start looking, but there's nothing like experience to shorten the search. Lee

__________________
"Knowing is not enough, we must apply.
Willing is not enough, we must do." Goethe

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1951 Chevy 3100

2003 Indian Chief Roadmaster

1983 GMC 1 ton Dually

1982 Chevy 1 ton Dually, service body (sold)

'90 GMC Suburban 6.2 "SS Veg-Burban"
(single tank WVO\diesel conversion) SOLD

'81 300D ~ Mama's car...my job (now my car)(but still my job) SOLD

'83 300sd ~ rescue car SOLD

2005 Ford Taurus (Mama's new car)(NOT my job!)

Park the car on a dry bit of pavement, refill the MS, pump the brakes a couple of times, then move the car. You could also have a helper push the brake pedal while you look under the car for leaks.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Could also be leaking into the brake booster.

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2009 E320 Bluetec 117,000
1995 E300D 306,000 Sold
1996 Ford Taurus LX 130,000 Sold
1985 300TD Still 225,000 Sold
2016 Ford Fusion 24,900

X2, It`s the Brake Booster. experienced the same thing, it was 1/2 full.

Replaced the MC and Booster. never get the Booster cleaned out good, and
didn`t know what damage the brake fluid would do to the Diaphram.

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The first place to look is a leaking rear wheel caliper. You might be able to see the leak with the vehicle on the ground, but possibly not. Remove both rear wheels and look for wetness behind the pads and beneath the caliper.

Yes, the m/c could be leaking into the booster, but it's not the first place I would look.

Thanks, guys! The wife had the car yesterday, but it's here today. Just got home from a PT appointment, the sun is out, it's almost 60*, and I'm going to go out and check now. If it's not the wheel cylinder, anybody have a bsllpark price on the booster? Thanks everybody!

__________________
"Knowing is not enough, we must apply.
Willing is not enough, we must do." Goethe

***********************************


1951 Chevy 3100

2003 Indian Chief Roadmaster

1983 GMC 1 ton Dually

1982 Chevy 1 ton Dually, service body (sold)

'90 GMC Suburban 6.2 "SS Veg-Burban"
(single tank WVO\diesel conversion) SOLD

'81 300D ~ Mama's car...my job (now my car)(but still my job) SOLD

'83 300sd ~ rescue car SOLD

2005 Ford Taurus (Mama's new car)(NOT my job!)

Its not the booster, its the MBC that is leaking. $85.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

I had a similar problem on my 85 300d. I mistakenly replaced the master cylinder, turned out to be leaky calipers.

Check those calipers good. You could pull the mc off the booster an d look In the booster with a flashlight for fluid. Be carefull, don't want to do too much driving on sketchy brakes.

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1996 E300 110,000
1985 300TD 212,000
1980 300D 238,000

The other day I posted on my wife's 81 300D having a brake fluid leak. There has always been a place behind the master cylinder that looks like it has leaked down the front of the booster, but never any low reservoir levels. Some of you said to check the calipers or wheel cylinders. This morning I checked and it looks like it's pretty on the inside of both front wheels. (Didn't take them off yet to get a real look) I've found caliper rebuild kits ($16), and rebuilt calipers ($70) and new calipers($$$). What say all of you about rebuilding calipers DIY style? Any pictorials? Any "Don't even think about it!"'s? I need to replace the rotors, anyway, so I figure, if it's not a real pain in the a**, I might give it a shot. What do you think? Thanks! Lee

__________________
"Knowing is not enough, we must apply.
Willing is not enough, we must do." Goethe

***********************************


1951 Chevy 3100

2003 Indian Chief Roadmaster

1983 GMC 1 ton Dually

1982 Chevy 1 ton Dually, service body (sold)

'90 GMC Suburban 6.2 "SS Veg-Burban"
(single tank WVO\diesel conversion) SOLD

'81 300D ~ Mama's car...my job (now my car)(but still my job) SOLD

'83 300sd ~ rescue car SOLD

2005 Ford Taurus (Mama's new car)(NOT my job!)

It depends on your level of experience and your patience. Getting the two pistons out of the bores is a challenge because once one piston is out.......there's a giant hole that must be plugged to allow you to force out the second piston.

Cleaning and getting the rust off the piston isn't too bad........unless water got into the cylinder........then, your rebuild project is over........you need a rebuilt caliper.

Installing the seal is no issue.

Installing the piston is difficult. The clearance is minimal and the piston wants to twist as it's going down..........furthermore, you don't have an easy way to use a C-clamp due to the confined space and the lack of a flat surface on the caliper. One additional point of note: On the caliper, outside the seal, is an area that is probably rusted. The rust buildup will definitely prevent the piston from going down into the cylinder. So, you must use some emery paper to completely eliminate the rust and raised metal in this area. It's a non-functional diameter, but it will stop the piston cold if you don't correct the issue.

Once the piston is installed successfully, you'll need three hands to install the boot........a real PITA to get it to snap into the groove on the caliper.

You can accomplish it if you're patient and have a bit of time.........don't say you weren't warned.........

When I was faced with this decision, rebuilts at O'Reilly were under $50. No brainer.

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Bob
'82 300D Petrol B-G Metallic

Me, I would get the rebuilts. Then I wouldn't spend the money on the kit, just to end up buying the calipers later. Besides, if you buy a rebuilt caliper and have any issue with it, it just goes right back to the parts store.
With rebuilt calipers and new rotors, you could do the entire front brake job in an hour or so.

I'd agree, if it weren't for the wheel bearings. Bearings alone are at least an hour to do right.

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Bob
'82 300D Petrol B-G Metallic

OK, I finally got back on here, and I can see where this is leading. For $17 bucks, I could rebuild the two front calipers with all the above described headaches, or spend $78 a piece and make it easy on myself. Not a hard decision, since I am a world class "wrench thrower" when I become disillusioned with the task at hand. Since it's February and my make believe garage is a mud hole right now, I'll try the rebuild some other day. Thanks for talking me out of it, boys! I almost went for it.

__________________
"Knowing is not enough, we must apply.
Willing is not enough, we must do." Goethe

***********************************


1951 Chevy 3100

2003 Indian Chief Roadmaster

1983 GMC 1 ton Dually

1982 Chevy 1 ton Dually, service body (sold)

'90 GMC Suburban 6.2 "SS Veg-Burban"
(single tank WVO\diesel conversion) SOLD

'81 300D ~ Mama's car...my job (now my car)(but still my job) SOLD

'83 300sd ~ rescue car SOLD

2005 Ford Taurus (Mama's new car)(NOT my job!)