Category Archives: Mechanical

Centrifugal.

The Renault had been making some unhappy noises from the engine bay recently, bad bearing kind of noises. I drove it to work and back and on the way home it decided to buck and jolt badly, feeling like a bearing jamming up (more on that later).

old pump

After having to purchase an 11mm wrench (not a real size, why it’s used is beyond me) I removed the water pump. Due to the design, it was impossible to remove by hand, as the bolts undo and the pump came off with a gentle tap, but the impeller got stuck in the aperture with the pulley wedged against the frame rail. A bit of wiggling and there was 1/8″ holding it back so a thump from the bottom of the mallet handle saw it liberated onto the floor.

coolant

I’m quite impressed by the coolant. It’s very clean, all things considered. This is a good thing.

water pump removed

Water pump aperture, including original gasket, which probably could have stayed, in hindsight. Note the really large space to work in (by general Renault standards, at least. I can get my hand in there and even see what I’m doing. Luxury).

gasket scraper

Spent an hour swearing at the old gasket, which was particularly awkward to remove.

no more gasket

Eventually it did come up clean. I’m just glad the block is cast iron because the angle I was forced to work at with the blade would have scratched and taken chunks out of any softer metal. Surprisingly also, the pump housing is remarkably rust free where the impeller spins, so I’m guessing this coolant does have some anti corrosion properties.

new pump

The new pump came with a new gasket (which didn’t fit very well, the holes didn’t line up properly) and has a different impeller design. Previous one was a pressed steel affair which was effective enough, had 4 vanes. This one is cast metal and has many more (and upon actually having run it now, pumps a much higher volume of coolant, particularly at idle).

sealant

Gave the gasket a coating of sealant and installed the bolts, which were held in place by the gasket (useful side effect of the holes not lining up well).

pump in place

There was a moderate period of jigsaw/Jenga type thought and experimentation that occurred before the pump went in. In the end, the bolts had to be in place, the pulley had to be on the shaft but not attached so the pulley could wobble about enough to allow access to put the pump in place. Thankfully there’s enough room to see one bolt past the frame rail and also space to stick a locking rod so the pulley bolts can be tightened.

alternator bracket

Then it was time to put things back on! Alternator and aircon compressor bracket assembly first.

alternator

Alternator with top adjustment bracket.

compressor

Finally, aircon compressor and belt, which took a while to remember which way round all the pulleys it goes.

battery

Finally, the battery tray and battery went back in. Filled up the coolant and let it burp as best it can with the engine off.

grubby

Been a while since I’ve had grubby hands, made a change from moving boxes and furniture.

running

Finally, all buttoned up, topped up and running. Aircon even works still, which is nice. There howling bearing noise is gone, but initially it was still bang thump, kangarooing and running intermittent badly on the test run. This was traced back to a rubber bungy that had split and fallen off one of the big spigots on the brake booster. Replaced that with a short length of pipe with a wire nut stuffed in the end because that shouldn’t split now. Normal, smooth running resumed. This fuel injection system really doesn’t do well with vacuum leaks at all.

It’s nice to have it back on the road, even if the front brakes are now sticking because they’ve not been used. Next job, that.

Wipe and wait

My car has a 4-position windshield wiper stalk; off, intermittent, slow, fast.

While the motor needs to be pulled and serviced because there’s little difference between slow and fast, the intermittent wipe had always been somewhat pathetic.

Selecting intermittent would make the relay click, and as soon as the wipers returned to the parked position, click again and they would almost immediately wipe again.

Pulled the dash shroud down and located the clicking box at the top left. (Top right is the key-in/seatbelt buzzer, bottom left the cruise control stalk, above that with the finned heat sink the dashboard dimmer control).

relay delay box

Took the circuit board out and drew up the circuit diagram by following the traces, to get a better understanding of the circuit and its method of operation.

board

Culprits were most likely the electrolytic capacitors. One had a high ESD and the other was meant to be 22uF, it measured in at about 100nF. Replaced them both. Now the wipers wipe and wait about 5 seconds before wiping again on intermittent, and added bonus, they now wipe 3 times after spraying screenwash onto the screen. Not bad for 45 minutes’ work and spares I had in stock.

Odds and ends

Been busy with Scouts events lately. First off was the Raingutter Regatta, which is an event where you build a boat from a kit and then race against other people with boats by blowing at the sail through a drinking straw.

Didn’t win any races but the boats were decorated that morning with Sharpie permanent markers. We have the Cheshire Cat from the latest edition of the Alice In Wonderland films, and Edvard Munch’s “The Scream”.

boats

That was a bit of fun. Next up was the Space Derby, which is basically elastic-band, propeller driven craft that fly along a zipline. Furthest wins, or first to the end of the run, which is about 30 feet or so of fishing line, held taut.

airplane

We went for a heavier design which won it first place in the races (not the fastest but it managed to gain the most momentum and coasted on by faster but shorter-traveled competitors). Designed after the P52 Mustang.

wheel off again

Took the wheels off the front of the car again, and changed the brake pads for new ones. The brakes had good pedal but offered little actual braking effort.

glazed

The pads were so glazed I could almost see my face. Plenty of friction material but all cracked up. In the bin they went. The brakes now work properly. That’s better.

Illumination

I recently fitted some LED bulbs to my reversing lights because LED and because they weren’t very bright. Unfortunately, the addition of LED’s didn’t really help. Most of the light was going back through the plastic of the reflector.

splish splash

Began by taking the worst lamp unit out and gave it a bit of a clean up in the sink. (Read: gave it a thorough clean with q-tips and soap and lots of water).

flash on

Taking a picture with the flash on shows that the reflector now reflects better because the plastic inside isn’t covered in grime and the reflective surface is a bit cleaner. However, the reversing light is still very dull.

dremel

Out with the Dremel.

lamp unit off

A bit of smoke and hot plastic later and the reflector housing is off. Indeed, the plastic is made from this kinda tan colored ABS which isn’t very reflective. You can just about see the remains of the silver paint that used to be on it at the bottom. Heat and age have made it all flake off.

taped up

Cleaned out and taped up the sections I didn’t want to paint. Stupidly I forgot to take a picture of the afterward, but I used shiny aluminum paint which, although not as shiny as the original chrome, is a lot better than how it was.

epoxy mix

Mixed up some “5 minute epoxy”, using the traditional matchstick and random piece of card.

epoxy

With a combination of cynoacrylate and the epoxy glue, I fixed the reflector back onto the lamp assembly.

polished

After a quick polish with some plastic polish, the result is visible.

light on the right

The light on the right is brighter than the one on the left now; before it was the other way around.

all bright

After going through the same rigamarole with the left light cluster, it looks a bit better than before.

buffed up

Machine polished the left lens because it was very scratched, particularly over the reflector. Looks better now, the white marking is where the plastic has crazed in the sun.
I think I’m going to be on the look for Renault 9 rear lights, because those actually line up with the rear swage line. For now though, these ones are working better.

Sensors and an unfortunate incident of unplanned ingestion

I’d planned for a while to change the intake air temperature sensor on the Renault because it had been reading a little “odd”- erratic and not really reflective of the world in general.
I ordered a replacement part- the closest I could get in terms of fitment is for a 1991 Jeep. The thermistor curve is the same as mine, as is the physical fitting. The only difference is the wiring connection.

undo

I don’t have a 19mm crow’s foot so slight tool abuse saw the old sensor undone.

old sensor

The offending article. Rather grubby (not that it really affects it) from being in the flow of fuel and air.

closeup

Closer inspection shows that the thermistor bead is cracked. That’ll be why the readings have been a bit strange.

comparison

Comparing old versus new. Same, barring the socket.

tools

Head inside into the warm to get set up with the tools required- I don’t have the proper Jeep socket so I decided that the heat of the engine in the location shouldn’t be so high to melt solder, so I would reuse the original connector.

chop chop

A quick spin of the Dremel later and the connectors are exposed.

trimmed and soldered

Trimmed the lugs down and soldered the old wires on.

heatshrink

I’d added a couple pieces of heat-shrink tubing to the wires before soldering them on. Fired up the propane torch outside to warm them up to shrink them down to the wires.

heatshrunk

A little bit toasted but shrunk down nicely.

reinserted

Inserted the new sensor and connected it all up. Noticeable difference now on cold start, before the oxygen sensor warms up and begins to give trim readings.

computer monitoring

I took the car for a drive and it was a lot better. When I got back I popped the hood to check on things and in doing so, leaned on the airbox, which was stone cold- that’s wrong for this kind of weather as the preheat damper valve should open up and draw warm air in from around the intake manifold. Took a bit of a looksee at what was going on. The vacuum operated valve was working when vacuum was applied to it. I took the throttle body hat off and found this:

thermo-valve

That’s about one-third of a thermostatic vacuum valve that controls the intake preheat damper flap. The rest of it is… gone. That will likely be the bad misfire the other day and the reason for the plugs being covered in dirt and having closed up, with bits of the valve being drawn into the cylinders and bashing about at the insides.

boroscope

I borrowed the 1979 Edmund Scientific fiber boroscope from work to have a look inside to see if there was anything left in the manifold that needed to be removed or any damage to the inside of the engine.

intake poke

Pushed it down the intake and had a look inside the manifold.

air sensor

It’s a bit difficult to get pictures from but that’s the new intake air sensor down the intake towards no.1 cylinder.

Took the plugs out and had a look in the bores.

crown

Top of one of the piston crowns. They all looked good. Put the mirror back on and took a look at the valves.

exhaust valve

Exhaust valve- looking good. A few signs of chips in the deposits in pots 1 and 2 but nothing substantial, thankfully. Looks like it broke up and was ejected in pieces out of the exhaust.

5 volts

Took a few readings from the throttle position sensor as it was acting a bit weird. Measured OK, and came up better after having been reconnected, so probable cause is a bad connection at the device. Back up and running, but I need to go to Dodge to see if they have the thermostatic valve.

Finding a leak that doesn’t exist, and a broken timepiece.

I’ve been having a hard time finding a few problematic issues with the Renault lately. Particularly it had started to leak power steering fluid quite badly, which would mark the floor where parked up and also get onto the auxiliary belt and make that slip.
Looking down from above, past the alternator and air conditioning compressor the pump looked rather wet, so I splashed out $14 and bought a full seal set for the pump. I decided to clean everything up with degreaser and refill the system, to hopefully see where the oil was leaking from.

dismantle

Begin by taking everything out, including battery, battery tray, moving the air conditioner comressor, remove the alternator and the brackets holding it all in.

empty

That leaves good access to the power steering pump. The corrugated plastic tube is the wiring for the front of the car, the braided hose is the gravity feed to the pump from the reservoir.

scrubbed up

Cleaned up the pump with an old toothbrush and engine degreaser. Rinsed it all down with warm water from the potato pump.

clean

Got a bit carried away as I had water left, so I cleaned down the inside of the hood where the oil had flicked off the belt, and the surrounding areas also. Topped up the oil and left it to dry overnight an in the sunshine.

full

Left it for two days, then checked on the level. Unfortunately the oil was all there still.

still oil

Another two days. Nope, there’s still all the oil left in there. The leak has miraculously fixed itself. Normally, hot, cold.. didn’t matter. It would leak regardless of it it was run or not. Now it’s not leaking!

clean pump

The pump is clean and dry, no signs of leakage.

oily frame

The only other place I can see is the return line, from the rack back up to the reservoir. If that has a crack or a pinhole it could be leaking. The engine cradle frame is a bit oily down under the back but I cannot see anything else that would be causing a leak. Further investigation to follow.

The second thing that irked me was the previously well-working clock had quit.

broken display

The display had taken to showing mostly nonsense, or nothing at all.

clock out

Took the dash to bits (again) and liberated the clock from the little cubbyhole it’s attached to.

polished

Cleaned up the smoked plastic section of the clock as it was all scratched and hazy.

components

Figured there were a couple pieces that might have failed and caused it to not work. Replaced the electrolytic capacitor and transistor. No joy.

circuit diagram

Followed the traces and built a diagram of what went where, to get a bit of an idea of how it all worked.

dead

Tested it but the chip was dead. No oscillator, just noise. The clock circuit boards are available, but they are a Jeep Wagoneer part, and as such suffer heavily from Jeep Tax and are therefore expensive.

zeroes

Upside-down image but poking power to the grid brought some nonsense up on the display so the VFD was all still good.

9

Poking about a bit more showed that some of the logic was alive, as various numbers could be liberated. Nothing sensible though.

led

Purchased a little LED clock with voltage and temperature capability for ten bucks, with the intention of fitting it into the clock as shown- looks OK but a little out of place and the very-bright display has no dimming capability.

dismantle

Decided to strip the board down and re-use the VFD, with the new clock module providing the logic. I’ve ordered a little 50V boost converter to drive the VFD, that will be proven to work first then I shall go ahead and get some high voltage transistors, pull the LED’s off the clock and use the output (multiplexed in the same way thankfully) to drive the VFD. Original clock, original display, just now with time, temperature and voltage display. Watch this space for updates.

Boosted.

The past week has been particularly clement in terms of weather- dry, sunny, cool. Unfortunately I have had a bad cold and had been stuck inside.

My brake booster did arrive though.

box

Today, I was feeling much better so decided to tackle fitting it.

clear a space

First thing to do, remove the master cylinder and move all the wires and pipes out of the way.

nut

Most of the nuts holding the booster on were fairly accessible behind the pedals.

ratchet

Deep socket, extension bar and fine angle ratchet made short(ish) work of it, lain upside down in the footwell.

clean

Took the old one out. Surprisingly clean under there.

old booster

The old servo liberated. $10 core return, $12 to ship. I think not.

new booster

Stuck the new one in the hole and bolted it in. Much label.

tidy

Tidied up the pipes and wires better.

done

Boshed it all back together. Had a fairly decent pedal despite having not bled the system up. Brakes now work. I’ll bleed the system up with the MityVac and go from there. Next up, power steering pump seals.

Pipe failure

I had noticed I was slowly losing coolant, and had attributed it to slight leakage at the head gasket but after running the engine up to very warm, the heater return line showed up something interesting. It began to bubble.

stained pipe

Decided to replace this piece of shaped molded pipe. Typically, the side easiest to get to came off, but the difficult to reach part had to be removed forcefully.
knife

Coolant still looks good though (it started out life yellow).

draining

I think it’s an interesting manufacturing flaw, there are 2 similar pinholes along the length of the pipe.

pinhole

Managed to find a roughly equivalent piece at the store.

replacement pipe

Got it all fitted up and bled.

new pipe in place

No more leaks!

radiator

…or are there? Radiator was a bit damp. Thankfully that is from where I’d opened the bleed screw on top of the radiator and it had percolated down the fins inside and come to the surface there.

Redux of the last few months.

It’s been a slow few months with little to report. I’ve lost faith in a few things, with a couple problems and issues with projects that had me baffled and I kinda lost interest in them.

However, things have picked up a little and I’ve gone back to the troubled projects or made some headway.

I bought some replacement tuning slugs for the Marantz receiver. They aren’t 100% the same permeability but they are the correct screw thread.

slugs

Replaced them in the transformer after carefully breaking the old ones up and getting them out of the core. Now I know what they feel like, the old ones were broken before I even started- the lack of decent radio reception certainly points to that.

radio waves

I got all set up and the thing refused to tune well. I could get a couple of strong local stations but the tuning meter and tune indicator would not light up, and those are partially controlled by the transformer. I connected my oscilloscope to the input side of the transformer to check the waveform was not distorted and all of a sudden, LOUD radio, strong signal! Uh.. yeah ok. Reflowed the solder, no effect.. touched the oscilloscope probe to the transformer again gently, and bingo. Strong signal. Touched my finger to it.. improvement. Okay, so it’s a capacitance issue. Experimented and ended up with a 10pF ceramic cap across the terminals to bolster the transformer. Now the selectivity and sensitivity are great. It’s right now the best radio I have in the house for FM stereo.

Carried on with it but now it keeps tripping out into protect. I’ve troubleshot the protect circuit, one of the other boards must have a leaky cap on it somewhere. I need to pull the boards power supplies off one by one and see what fixes it.

Next up, refinished the floors at the house. Edging strip all done in the kitchen:

kitchen skirting board

Finished up in the utility room, flooring strip and the paneling done:

utility room door

Finished up the cabinet around the water heater:

water heater

Pulled the stove to bits and thoroughly cleaned it, the glass particularly was vile.

stove

Finished the floor edge strip in the living room, split the flooring between the two rooms where it was buckling and added a divider to allow for expansion.

living room floor

Rented a floor sanding machine and sanded the floors back, as previously they had looked OK, but having painted the walls and tidied up they were the least well-finished parts of the room.

floor sander

Solid cypress flooring. Smelled real nice when lain bare.

floor stripped

A few coats of polyurethane clear varnish later:

shiny

Looking much better. Also, picked up a nice Holophane light fitting on clearance for $4 at Home Depot. Fitted an LED light to it that has 4 segments inside, looks rather like a standard light bulb:

light fitting

Been troubleshooting the brakes on the car for a while. Stumbled across a post on a Ford Explorer forum with the same symptoms as mine. Turned out to be a faulty brake booster servo. I’m going to vacuum test mine this afternoon, have my MityVac for the purpose (shown here with brake bleeding catch-can fitted):

MityVac

Also picked up a GTE Palco payphone, which has gone into service here at the house, with the requirement for coin removed.

GTE Palco payphone

I repaired a little Realistic PA amplifier that got struck by lightning, and built a cardboard speaker to test it with.

amp and speaker

Also cleaned out and got fixed up the Kerosene lantern, for hurricane use.

kero lantern

That’s about it for now.

Reflective! Also, frosty.

Bought a mirror from a gentleman in Canada.

mirror

Bottom one (old) being held up. Sunshine and humidity made all the silver fall off. The new one looks new by comparison.

Also moved the car and mowed because the grass is growing fast this season.

grass

That’s 4 days’ worth of grass growing around here.

frozen

Also the new heater element arrived for the freezer. Not a day too soon, it was beginning to freeze up. That again was 4 days’ of ice.