Water Pump

[rogerch]

Question Number 5

How the @#$%^&**** do you get the bottom pulley off. there seems to be no room for a puller.

[lotus4s]

You're right, not much room for a puller. It's not a tight press fit and should come off fairly easy unless it's corroded on. Try tapping the pulley with a dead blow hammer, possibly some penetrating oil and try to pry it gently from behind.

If no joy, you can use a little heat on the pulley but try to avoid getting the crank too hot so as not to destroy the front main seal behind it. Concentrate the heat on the pulley.

Use anti-seize on re-assembly.

Are you doing the cam belt while you're there? Otherwise you don't really have to remove the crank pulley.

Edited March 26, 2011 by lotus4s

[Rich H]

I used a piece of 1/4" steel plate tapped in 4 places, 3 places so the bold heads and big washers would grip the edge of the pulley and the last one so it hit the loosened crank bolt.

Wind all the bolts tight and it popped off.

It was not coming off any other way!

Beware of hitting it too hard - it's cast ali.

[rogerch]

It was corroded, so I ended up making a puller that I could fit in the space available. I was quite stunned when I got it off and found it was alloy.

Glad I hadn't hit it too hard.

Onward and upward, I might get the belt off tomorrow !

[Rich H]

Neat, a lick of the grinder and then sell it on e-bay!

[rogerch]

I'll paint it next time I have the spray-gun out. But I was in a hurry to use it today.

[andydclements]

It was quite funny when Newts and I were doing his brake vac pump and it was at a hired workshop. The owner does other car services as well (best not mention Dave Freeman's manifold). He was saying how he's make a much lighter pulley than that. he'd turn one out of aluminium, so I handed him the pulley to feel the weight, he accepted he's unlikely to be able to save any weight that way.

[rogerch]

Question Number 6

Between which 2 pulleys are you supposed to measure the belt tension ? I always though it was over the longest single span, which looks like between the exhaust pulley and the bottom pulley.

But you can't get a Burroughs gauge in there with engine in situ, Next longest is inlet cam to distributor/ oil pump drive. Either was the existing belt seems way / dangerously loose.

[stevem]

Hi Roger, take a reading on the top bewteen the distributor pulley and the intake pulley, right in the middle. The yellow quadrant on the gauge you have is for a new belt, green for normal, red for "it's getting a bit slack", and off the scale in teh white bit for "oh shit I had better do something about this quickly."

The belt gets tighter when the engine is hot after a run too, so I usually check it when warmish but not stone cold, and at about 30 DBTDC. I get a slightly different reading from one day to the next, but if it's in that green quadrant it's good.

[rogerch]

Question number 7

Will this stuff Permatex Ultra Blue, do for the sealant for the water pump ? I've got it because I can't get Hymalar My concern is heat.

Permatex Product sheet Clicky

[Rich H]

SJ sportscars sold me "Wellseal" which seems to work.

Sticks like sh!t to a blanket...

[lotus4s]

Steve,

Hate to disagree with you but if Roger is going to set tension using a proper Lotus Burroughs gauge, the engine should be cold (ambient temp) and at TDC. Any other settings or temps will invalidate the reading on the gauge. If using a generic Burroughs then I have no idea what it should read. All this info is according to the Service Notes.

Checking tension with a Clavis gauge or other frequency tester like Tune-It software, then the crank should be at 30 degrees BTDC.

Roger,

Are you using a gasket on the water pump? If so then most any gasket sealant will be fine. If installing without a gasket, the manual calls for Permabond A136 and if you don't have that then something like Loctite 518, Permatex Anaerobic Gasket Maker or similar anaerobic flange sealant should be used.

[rogerch]

Question Number 8

The pump is still not off !!! I have had to remove the timing sprocket to get to one of the bolts, but it's keyed and now marked so should go back as was.

The vacuum pump is proving a hindrance, how may bolts hold it on ? I can only find one.

Due to ops and stuff last year I can't lie across the engine and working from underneath has it limitations. I'll have the same agg putting it back together so I may as well make it easy on myself. So off with the vacuum pump.

Anyone know what size Allen key ? I can't get one in there until I cut it down, so can't check the size.

Edited March 28, 2011 by Roger the Dodger

[stevem]

Hi Jim

The burrough's gauge that I loaned to Roger is almost identical to a 'Lotus version' that DanR has but was supplied with a generic scale on it's face. I took a reference reading on the Lotus gauge by checking the tension on both Danny's and my Esprit and then transferred the Lotus gauge markings onto the Burrough's gauge so that they read the same on the scale.

You are correct , the manual does say to check at TDC, but I have found that the reading is within the green band where ever the engine stops. 30BTDC was from notes I had referring to a Krikit gauge. ( my mistake ) It doesn't seem to make much difference though. This Burrough's gauge is way more accurate than my Krikit gauge which I eventually gave up on as it never gave the same reading twice.

I found on my 88 Turbo, that if the belt tension is set on a cold engine, it gets way too tight when hot. ( off the top of the scale ) I found that tensioning the belt on a warm engine ( just left ticking over for a few minutes ) set so that the gauge measures in the middle of the green quadrant. This then shows that the tension reads in the yellow quadrant when hot, so both readings are in the right range. At cold it's just on the low end of green. That is the only way I can get the tension to stay within the specified range. It doesn't seem to be an exact science, more a case of getting the readings in the right ballpark. I guess with a 23 year old car things have a bit more 'tolerance' grown into them as the newness has worn off. The manual even suggests taking 3 readings and using the average after rotating the engine 360 between each reading.

I also did a frequency check of the belt when 'twanged' and it varies between 107 and 112 Hz , which is about A2 on the chromatic scale. ( checked with a Hameg frequency counter and Oscilloscope from the workshop at work )

Roger

Only two bolts for the vac pump as far as I remember, the allen head bolt at the bottom that sets the tension, and another one up near the top. I replaced the allen bolt with a Hex bolt, but can't remember what size it was. i don't remember having to cut my key down though. The vac pump doesn't seem to be mentioned in the service manual I have.

Edited March 28, 2011 by stevem

[rogerch]

I have it all off now (I'd like to start an appreciation society for the guy who came up with that vacuum pump bracket, that Allen bolt is a gem) I'll be putting a hex back in it's place.

I've got the hub off the pump and I'm just familiarising myself with the order of proceedings for pressing the old assembly out and the new one in.

[lotus4s]

Steve,

When you say you're belt gets way too tight when set cold and the engine hot, does it whine?

I agree that the belt does get significantly tighter with the engine warm and it would be normal for the reading to be off the Burroughs scale with the engine hot which is the reason that it's set at ambient temp. The problem with setting on a warm engine is you're entering an arbitrary factor, what temp is the engine 40, 50, 70, 80 degrees C and how much has it expanded to affect the belt tension at that point?

I understand that you basically have calibrated your gauge to Dan's Lotus gauge but when was the last time his gauge was calibrated? Like any spring scale, torque wrench etc, they have to be checked and adjusted periodically.

I've also recently started leaning towards the frequency method to tension belts as I think it's more reliable and easier to do than using a Burroughs or Kricket. When you said you checked your belt at 107-112Hz was that at 30 BTDC and at what engine temp?

The only time I've run into a problem with the belt getting too tight (and whining) when hot is with the new Gates blue belt. It seems to be much more critical on the tension setting and needing to be set at the lower end of the scale when new as they don't stretch much at all.

I'm not trying to give you a hard time, it's just I'm a pretty big believer in doing things by the book when it comes to something as critical as a timing belt. Your method may work fine for you and that's great but it might cause a problem for the next newbie that reads this thread and does his timing belt for the first time. If done by Lotus standards it will always work.

Cheers,

Jim

Edited March 28, 2011 by lotus4s

[rogerch]

Question Number 9

Is there any way of testing the pump before putting it back on. The amount of work involved in getting it off, you don't want to get it all re-assembled and find it still leaks. I'm just getting nervous now, the bearing is about a mm recessed rather than flush, I'm wondering what effect that may have on the seal. Probably nothing, but.

There again I don't want to go ripping it all apart again, because the seal may not survive.

[stevem]

Steve,

When you say you're belt gets way too tight when set cold and the engine hot, does it whine?

Cheers,

Jim

Hi Jim

Yes the belt was whining a little when hot, however that was a few months ago when it was a new belt and I backed the tension off a little immediately. When Roger has finished doing his belt I will get the gauge back and have another go. When I mentioned checking with a warm engine, the temp gauge only just started to move up the scale to 30/40 after ticking over in the garage for a few minutes. The frequency test was done at about 30 BTDC.

last week when I checked the belt before sending the gauge to Roger, it measured within the green segment on the gauge. I'm sure it will be fine, the old belt had been on 3 years and was quite slack compared to this one. Thanks for caring While I have you, riddle me this.... when the engine has been sat for a day or two and it's cold, the belt is slacker than if you turn it over a couple of times first to take up tension/slack. Which reading is correct ? ( maybe that's why we should take an average of 3 - answered my own question. )

Hi Roger

Sorry to hijack your thread, but I reckon follow Jim's advice for tensioning your belt and it will all be good. It's got to be better than doing the 90 degree twist and he sounds more clued up than I am. I'm sure the Burrough's gauge is fine.

To anyone else reading this thread, a tip when trying to put that bastard air-con belt back on after a belt change - Slip the belt over the A/C pully and onto the main Crank/Aux pulley before you put the pully back on the shaft. It slides straight on.

Edited March 29, 2011 by stevem

[lotus4s]

And that is a great tip on the ac/crank pulley.

[rogerch]

This is a 1988 Stevens, there was no water pump housing gasket. Conclusion, this is not the first time the pump has been off.

Now it is entirely possible the pump has been off and the bearing and seal not changed, how ever the condition of that seal is less than good. If it is the second one, it's even less good.

However, I'm trying to decide if the seal is just perished or overheated. What do you think ?

[andydclements]

I thought only the early cars had gaskets.

[Rich H]

Probably a bit of both, perished a bit, friction increases and then heats it up.

[dodge1979]

Well I picked up my water pump repair kit yesterday from Lotusbits..havent had chance to look through it yet, thats next weekends job but with regards to a few things...I bodged together a similar pulling type tool to get the bottom pully off...but it ended up cracking as it was proper stuck on! Not the end of the world but still should get another one in a week or so when they get stock in. Also, my pump had no gasket on it either. Im just going to use an RTV to seal it on. I am, however, changing the front crank seal..well infact all seals while Im at it.But I guess thats easier for me as my engine is out of the car! Good tips though on the rebuild of the pump...just write down each measurement take some pics and the reassemblyshould go well!

Darren

[rogerch]

Question Number 10

How many revolutions do you have to turn the engine to return all the marks on the belt to their original position ? Both can shaft pulleys, bottom pulley and distributor drive.

I'm almost finished ! But I'll do the brake master cylinder whilst it's still up on stands. The belt is just a smidgen slack, but tight as buggery compared to the one I took off ! I'll check it again after I've run the engine for half an hour.

[Rich H]

Not really sure what you are asking but the cams run at half the speed of the crank so all the marks should line up after 2 revolutions of the crank.

Good work!