stupid primer pump question
 

Did a search and found lots of info on the primer pump.

Car sitting for over a year...

Mine appears to be dry. As soon as I unscrewed it and pulled it back there was fuel already in the pump. I started pumping and it feels like it's pumping up but the outside of the pump plunger/shaft/cylinder thing is wet with fuel.

From all the posts I've read, these things should not leak at all or air gets into the system.

Am I to understand that when you pull the pump plunger back it should be bone dry all the time?

Or is the presence of fuel on the plunger shaft ok as long as the primer pump does not leak fuel when it is screwed down/in or squirt/spray fuel when the plunger is pushed in?

To put it simply; you should never get any fuel on your hands at any time while operating this pump. They can suck air and are cheap to replace.

Peter

Called Auto Zone, Pep Boys, O'Riely, etc...no one even lists this item.

Any source besides the dealer?

No fuel on the hands...okay. I thought maybe the shaft might be a little wet to lubricate the pump. Sounds like wishfull thinking on my part.

If the primer pump is leaking, will the engine never start or run? Will it even fire or sputter? Or does it depend on the severity of the leak so that it may still start, just run like crap and die.

I'm hoping to here it fire just once for a little encouragement before I begin buying parts.

Fastlane should have them.

Peter

Fastlane? is that a retail parts store or internet place?

At the top of the page, third tab from the left. The are one of the sources of income for this wonderful web site. Partsman Phil is great and the parts are usually delivered quickly. Cost for your pump should be somewhere in the ballpark of $12.

Odie,

I just noticed from your posts that you are a newbie. Welcome aboard. Fast Lane is part of this web site. When people buy parts from MercedesShop.com part of the money goes to fund this web site. You should be able to go to the home page and click on fast lane.


Peter

Welcome odie!

I have found that all of the local parts places are useless when trying to get parts for my car. Autozone lists light bulbs, thats about it. Order your parts from Fastlane or Phil, I have placed many orders with both and have been extremly happy with the level of service I get. You also get good German parts not cheap aftermarket crap, half the stuff I get is OE because their is no aftermarket part. Also only use German oil filters they are better.

A small leakage at the primer pump may not necessarily prevent it from starting, although it will not run right if it's sucking air. Generally speaking, if the main fuel filter is full and you have a good battery and good glow plugs, you should be able to get it started.

Here's a little tip on replacing the primer pump. If you disconnect the prefilter, the nipple on top of the pump where the prefilter hose connects can be unscrewed. Taking that off will allow you more room to get a wrench on the bottom of the primer pump.

I'll bring in a fresh battery and a couple gallons of diesel tomorrow and see if I can get it started. If it runs, game on! Filters, primer, fluids, etc...

Well, my primer pump started leaking and the car is hard to start, so I guess it's draining down. can you pull the pump and replace the gasket? I've never used the pump and it wasn't screwed on too tight, but it's leaking where the pump fits to the housing. Thanks to all that can help.

Odie,

You've been keeping secrets. You didn't say the car didn't start. Replacing the hand pump may not solve your problem. Do not use ether and glow plugs to start the car. Use a battery charger or good jumper cables. If it doesn't start, post again, because there are other tricks.

Peter

fj,

Are you sure the leak is at the bottom?

odie, to start off, get yourself the two new diesel filters (the small plastic one and the larger screw-on filter)

Also check out my thread of the new primer pump, its well worth it and its cheap:

http://www.peachparts.com/shopforum/diesel-discussion/92728-engine-wants-turn-off-idle.html?highlight=adiel


Also:

You don't need to replace the gasket, just get the new primer pump, it comes with a new gasket. Like someone mentioned here it's around $12 and it is a BOSCH brand part totally re-designed so you can't go wrong. Also, like they mentioned on here, it's alot better to get stuff for these Mercedes online like at FASTLANE or RUSTY. (I dont work for neither of these two companies) Local autoparts do not carry this stuff.

Thanks,
Adiel

As Fastlane do not send parts overseas, I cannot use Rusty's services. I would if I could, because this is one COOL site.
I simply went to my closest Injector service centre and purchased a new priming pump for my Bosch IP. They handed over the little black cylinder and I handed over Aus$21.

As the lift pump is awkward to access to replace the primer, I removed the hoses and the 2 nuts from the lift pump and took it into the workshop to fit the new primer.
Took less than 1/2 hour in total.

To clarify....the car has been sitting in impound for over a year. To anyones knowledge here the car has not been started in a long time.

I know that the motor will turn over, the glow plug light comes on and then goes out, fuel guage reads empty, primer pump has fuel in it.

I have not yet tried to start it as my little jumper cables can't handle the totally dead battery and starter. I just got the keys Monday and the car is sitting in the parking lot on base.

I going to put the fresh battery in and see what happens. There is no local souce for the primer pump. Before I start ordering parts (several days wait) and changing a bunch of stuff, I'd just like to actually see if this beast will run. Or at least fire a couple of times.

I'll give it a shot at lunch and give you guys an update.

Good luck, mine still hasn't started. Been about 4 days now of playing.

:) I don't want to scare you off but...If you are low on budget, these cars might not be exactly right for you. The two diesel filters should not run you more than $10 (these you can pickup at a local autoparts) and will not hurt that you change them BEFORE you attempt to start the car. You can leave changing the primer pump for later. These old cars require that you be on top of them even though they are very reliable. But, God willing, I would never trade my 1983 300D Mercedes because I enjoy working on the car...plus its a diesel so it's pretty cool to drive around. I hope you can enjoy the car and the forum as much as everyone else on here.

Adiel

Odie you're in Copperas Cove correct? Temple isn't that far away, Garlyn Shelton Mercedes on HK Dodgen Loop can get you the primer pump if they don't have one in stock. Or you can always call the 1-800-for Mercedes number and have their roadside tech come out there with his own big battery and help you start the car. It's free. Don't mention to them that it's been sitting, though it probably wouldn't matter. Starting a diesel benz that has been sitting over a year SHOULD be a piece of cake.

"fuel guage reads empty"
UH.... might want to correct this also.... no telling what kind of difference some fuel would make...

CC... I took that to mean Corpus Christy....

well i put two and two together (army base and CC) and got Copperas Cove. Killeen doesn't have an MB dealer and neither does Copperas Cove, so that explains why he can't get parts locally. Corpus Christi has an MB dealer.

primer pump...O.K. so I don't know just what's going on!
 

I looked under everything I could think of in the search and couldn't find an answer. I want to know what to expect when the hand pump is pumped? I recently removed the injector lines to gain easy access to the glow plugs. After reinstalling the lines, with the nuts at the injectors still loose, I pumped the hand pump till I was blue in the face, expecting to see weeping at the nuts. I didn't see fuel so I thought the hand pump was bad so I tightened the nuts and cranked a long time till it started.

I just changed a couple of glow plugs on my other car and also replaced the hand pump on it just for kicks. While the injector lines were still sitting on the air cleaner, I pumped until I heard the squishing sound. I thought I would see the fuel coming out of one or some of the ports of the injector pump and didn't. After a little pondering, I believe that the pumping action only pulls fuel from the tank and charges the filters and fills the injector pump.

To get the fuel lines full, I think that I will need to use the LarryBible trick of leaving the injector lines one turn loose at the injectors and have Wifeypoo crank and I'll tighten them one at a time as they weep.

Am I on the right track or what?

Yes,
The only way to prime the rigid injector lines is to crank the engine. It is best to ensure that the injector pump is primed by loosening the banjo on the IP return line and pumping the primer until the air bubbles cease, then tightening the banjo bolt.

Youi can get three possible reactions from the primer pump with two of them being wrong. If you pull up on the pump and feel some resistance, and push down and feel more resistance, but the pump goes to the bottom smoothly, you are drawing and expelling fuel. This is good. If you can push and pull the pump with no resistence, you are out of fuel. If you pull the pump up and it sucks itself part way back down without your help, a vacuum is being created in the line, because the screen in the tank is clogged with fungus.

Peter

thanks fellas, and a reply all the way from the other side of the planet, can you believe it? And Peter, I haven't forgot that invitation, I'll call you one day soon and stop by for a visit....Ernie