Water Pump Replacement

The Minutiæ

Created: 12/30/01

Author/source: Peter Lucas

This document provides still more details on Waterpump change instructions and DMC Waterpump Details. Be sure to read both of these articles first.

The above cited articles are wonderful resources that made it possible for me to replace my DeLorean's water pump. In addition to saving hundreds of dollars, I learned a huge amount about my engine, gained confidence as a mechanic and also had the opportunity to clean and detail my engine in the process.

Although these resources are excellent, the process was still a little scary, due to the many wires, hoses, and miscellaneous doodads that must be removed and reinstalled in the process of this rather complex procedure. As a service to future adventurers, I decided to attempt to document each and every wire, hose, bolt and washer that needs to be removed in the course of this procedure and publish it as a checklist.

This document is the result.

So here's the plan:
Print out a copy of this note to be used as a checklist. Do everything mentioned here in exactly the order listed. Relax. No single step is difficult, the only challenge involves getting lost in all the details. Take your time. Clean everything up nice and shiny as you remove it. Clear yourself a large, clean area and line everything up in exactly the order that they were removed. Your engine will look very scary by the time you get to the end of the checklist. DON'T PANIC! It will all go back together just fine. Simply start at the end of the checklist and work your way back up. Relax. This procedure is a rite of passage of sorts--dividing the men and women from the boys and girls, so to speak. By the time you finish it you will think of yourself as a real live Delorean mechanic. Did I mention to relax? Good. Now go for it.

NOTES:

In this document the term "FRONT" means "toward the front of the engine", i.e., farthest away from you as you work on the engine. There is a tendency to slip into thinking of the rear of the engine as the front, since it is closest to you. Pay attention.
I have tried to document literally every single step necessary to replace your water pump and associated hoses, down to the last tie-wrap and washer. I'm sure I missed a few things, so if you use this document, please note any discrepancies and send them to me via the DML. I will try to keep track of all corrections or additions.
When reinstalling bolts, it is a good idea to use anti-sieze compound in most locations, especially where steel meets aluminum (see below).
You will need many new gaskets, O-rings and crush washers. Order the whole kit from your favorite Delorean supplier. Give some serious thought to replacing those deeply-buried sensors, hoses, spark plugs, and distributor that will soon become very (but briefly) accessible.
In addition to this and the previous two tech notes, you should also carefully read sections C:12 and C:13 of the shop manual, and study the corresponding sections of the parts manual.
Get yourself a torque wrench and use it. When reinstalling parts, check the shop manual for correct torque specifications, especially the fuel system banjo bolts.
Things that can go wrong:

The most common problem associated with this procedure is vacuum leaks and misrouted vacuum hoses. Several of the connections must be made semi blind. Pay careful attention as you remove them. Label everything. Take pictures.
If there is any question about the integrity of the hoses themselves, replace them. You don't want to go through all of this again to replace a $4.00 part.
A more serious problem that occasionally happens is broken bolts or studs. Steel bolts in aluminum engine parts can be troublesome, especially the bolts that hold the manifold to the block. Use lots of penetrating oil. Be gentle. Instead of forcing a stubborn bolt, give it a good soaking and let it sit overnight. Use good tools. Lead a good clean life. Be kind to children and small animals. Hope the last guy used anti-sieze compound. Pray.
Be sure to keep everything clean, clean, clean -- especially the fuel system parts.

OK, ready? Let's go:

Remove air cleaner.

3 bolts

Remove throttle drip shield

1 bolt

Free hoses and wire harness

Cut wire tie that secures fuel line to bracket on left manifold
Cut wire tie that secures 4 fuel and air lines at left side of engine
Unclip wire harness in two places: (a) top of manifold, (b) right side of manifold

Loosen lower air casing attachments to intake manifold

2 capscrews (with washers)
one bolt (with washer)
wire clip held by left capscrew

Idle speed control

unscrew clamp on idle speed control hose and detach hose
pull hose and pipe from lower air casing.

NOTE: Pay attention to this step. The copper pipe is held in place with an 0 ring hidden in the side of the air casing where it is difficult to see. It is hard to get back in place and a major source of air leaks if you don't get it right.

unplug black electrical connector from idle speed regulator
remove regulator and hose to cold start injector

two capscrews (and washers)

Electrical connections

unplug blue electrical connector from cold start valve
unplug white electrical connector from control pressure regulator

Fuel hoses

remove a total of 13 fuel hoses from the fuel distributor. Make a picture and label all hoses.

12 banjo bolts (and two crush washers each)
1 double banjo bolt (and three crush washers)

NOTE: Crush washers must be replaced with new ones. Do not reuse them.

Solenoid valve (in front of lower air casing)

remove wire from solenoid (label it S1)
remove front hose from solenoid (label it S2)
remove rear hose from solenoid (label it S3)

Prepare lower air casing for removal

disconnect throttle idle microswitch wires

Black wire on bottom terminal
Green/black wire on top terminal

disconnect lower vacuum hose from lower air casing.

Note: be sure to reinstall this hose before reinstalling lower air casing. It is very difficult to reach later.

Remove lower air casing

retrieve 2 large O-rings from rear of throttle valve assembly

Remove inter inlet manifold pipe

3 bolts (and washers)
wire retainer (held by right lower bolt)
2 plastic back up rings
2 paper gaskets on manifold

Remove wiring

unplug plastic plug (4 wires) from full-throttle switch
unclip tie-wrap holding these 4 wires to cable

unclip 3 spark plug wires from right front of manifold

Remove throttle spool assembly

remove quadrant arm from throttle linkage ball (1 wire clip)
3 bolts (and washers)

Inlet manifold

remove 2 large hoses from front of manifold

label left one ML
label right one MR

remove two ground wires from left front of manifold
remove small vacuum hose from left front of manifold (label it MLV)
remove 2 hoses from cold start injector

label top one CT
label bottom one CB

unplug ground wire from right front of manifold
detach 2 spark plug wires from cold start injector
remove inlet manifold (4 bolts and washers)
retrieve 6 O-rings from inlet ports

Water pump

remove 2 large hoses from water pump
remove hose bracket (1 bolt & 2 washers)
unplug cable to thermotime switch on water pump
remove thermostat housing (2 screws & washers)
loosen 4 hoses to water pump
remove alternator belt
remove water pump (3 bolts & washers)

Coolant distribution pipe

remove wire from lambda thermal switch (on coolant distribution pipe)
remove wire from idle speed thermistor (on coolant distribution pipe)
unplug three air tubes from thermal vacuum control valve (on coolant distribution pipe)

label left tube TVL
label center tube TVC
label right tube TVR

remove distribution pipe (4 bolts & washers)
retrieve 2 O-rings from under pipe

This is as far as we go. Pretty cool, huh? Now would be a good time to impress your spouse with your skill and daring. Take a break. Then get to work cleaning up all that crud you have uncovered. When everything is spic and span, get out your shiny new water pump and start working your way back up the checklist. Be careful with O-rings and don't overtorque anything. Relax. When you get to the top of the list, start her up, top up the anti-freeze, purge the system, then go for a ride. Finally, send a note to the DML letting us know how it went.

Have fun!

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