After spewing a lot of brake fluid from the reservoir during a front caliper collapse to install new brake pads, my 1994 B250 3.9 bare bones service van has developed a problem I need to resolve immediately.

The van drove fine for 20+ miles after the DIY brake job. Gradually, the engine started making a louder + higher RPM sound. I thought someone with a louder truck was approaching me revving their engine. I heard a little bit of a whining/whirring sound accompanied by a slight clicking/bearing rattle sound that one might hear when a water pump is failing in the engine compartment.

I realized I was losing momentum as though the transmission was slipping so I pulled into a kwik mart and checked the tranny fluid but it was fine. As I left the parking lot, everything seemed to have resolved itself and did fine for a few blocks then it seemed the tranny was slipping again and the engine revved too high for the speed I was traveling.

I am unable to reach a speed greater than 40 MPH without the van sounding like it's going to blow up from over revving/high RPM. ... I can hear the transmission shift through all the gears just fine so I'm sure there's no problem with slippage, although I don't really (for sure) hear it going into 4th gear - overdrive - torque lock or whatever it is that this model van has, but that's not saying that it does or it doesn't shift into it, I just can't hear it from all the noise the over-revved engine is making.

I did a reset on the new ECM I had just installed about a year and a half ago by unhooking the battery for overnight. That didn't help.
Later, I did the key dance and came up with a couple of codes, notwithstanding the typical 12 and 55.
The one that concerns me is code 45, the overdrive solenoid - open or shorted. and I don't know why code 33 comes up. There's no A/C in the van.

My question is this ... Under the brake master cylinder where there are relays and several connections of all sorts, is it possible that the massive quantity of brake fluid that spilled onto a lot of those relays and connections somehow shorted something out in that vicinity and THAT'S what caused the problem? Will separating and cleaning/drying out as many of the connections and relays resolve this? The van is running and stopping just fine otherwise.

I'm open to all professional advice and suggestions. Customers are patiently waiting on me.
Thanks,
John

 

Well, cleaning all of the connections and relays with electronic cleaner and drying them out did not help anything.
Still only getting Codes 12 - 45 - 33 and 55.
Next step?

 

Did you check behind the vacuum booster for wiring damage? I know that brake fluid destroys certain types of plastic, maybe something behind the brake booster is damaged or shorting out.

I would also carefully detach the wiring harness that runs along the firewall and check everything, including the fusible links, for damage.

There is also a bolt for common ground located under (beside?) your battery if memory serves. You might want to unscrew that, wire brush or wheel the firewall, clean the lugs and reattach.

 

Thanks Rusty. Yes, I've done all that, including taking apart all of the connections, relays and such then cleaning them with electronic spray cleaner, drying them with compressed air and reconnecting everything.

Since I've been leaning toward the 45 fault code as the problem, I've traced all the wires & plugs to and from the transmission and cleaned and dried all of them too. There was a lot of moisture that dripped out of one of the plugs that I pulled off of the side of the transmission which appeared to be what may have been the overdrive solenoid, not really sure. It was a three prong horizontal plug on the drivers side.

After doing all that, I took the van out and everything was back to normal. The transmission shifted fine, the engine sounded fine, no high RPMs from the engine or anything unusual. I felt good that I had fixed it and saved money.

Then I thought I better put it to a real test and took off from a stop sign in a hurry with a little harder acceleration and it started all over again. So I'm back to where I started, in limp mode. I'm going to take a break and let it cool off for a little while and try another test drive. I plan on driving it tomorrow morning regardless as I have three customers scheduled for the day.

Do the symptoms sound like anything other than an overdrive solenoid open circuit or short to you?

 

Your van's behavior could be attributed to quite a few things, but I thought you suspected your brake fluid spill as the culprit, or at least the catalyst. Have you changed your mind?

If you are feeling brave you can unplug the connector and one of two things will probably happen; you will lose your speedo OR your overdrive. If your problem goes away you probably have a shorted overdrive solenoid - replace it. If you lose your speedo then you obviously have the wrong connector and you should refer to the proper manual(s) to find the location of the overdrive solenoid.

 

just guessing but inside your wiring harness somewhere is excessively wet w/brakefluid
good luck and quit cussing

 

Yes, I've changed my mind. Nearly $1300.00 worth of change. Apparently the transmission problem was coincidental to the brake fluid spill. After checking, cleaning and drying everything I thought to be effected by the spill, the transmission problem remained so I took the van to the local transmission mechanic and subsequently had it rebuilt.

It turns out that I have the 727 TorqueFlight transmission. There is no such thing as overdrive in this tranny. The friction plates were worn down to nothing.

Since the inception of the vans manufacture date, it has always been subjected to a heavily loaded cargo area, even to this day with all of the heavy tools I have loaded on it and this is what contributed to the wear on the friction plates according to the mechanic.

Everything was replaced in the rebuild including a new torque converter. Now the van is running and sounding like a new van. The only thing that concerns me is ... when I asked the mechanic what kind of fluid he used to refill it with, he told me ATF-4. While waiting around for my fan clutch to be replaced, I was perusing the invoice and noticed it said that Dextron III was used to fill it. I confronted him about it and his claim was that they didn't know what was going on at the front desk and just wrote that down and that he himself put the ATF-4 in it so he KNEW what was in it.

I also discovered that the ECM which I replaced over a year ago was apparently from a van that had Air Conditioning and Overdrive, hence the code 33 and 45 kept coming up on keydance, and still do even after the transmission rebuild. These codes have nothing to do with my van, rather the previous van that the ECM was removed from.

Thanks for all the input.