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New Owners of a 1987 Allante.....

21K views 60 replies 7 participants last post by  DopeStar 156 
#1 ·
My girlfriend's dad gave her an 87 Allante he bought in non-running condition. He's currently working on the car so it runs (ignition system/distributor issue) and as soon as it does we're taking possession of it. I don't have any pictures of it yet, but I do have the owner's manual and full service manual in my posession. This won't be a daily driver for her, it'll be a weekend fun car, or something for cruise nights or events in the Cadillac Club I belong to. I have a few questions about this car since it's out of my Cadillac expertise....

1. My 89 brochure shows the Allante having optional analog gauges, but the owner's manual for our 87 shows only the bar graph digital version. Was this the only kind offered in 87?

2. Were there any common problems to keep an eye out for? I know this car has the HT4100 engine which is dreaded in the large RWD cars, but how does it fare in the small Italian Pininfarina body? Any tips on how to keep it happy?

3. I know the car needs a new grille (broken tooth) and perhaps a new front bumper (small crack where someone must've hit a parking brick) so my question is how easy or impossible are parts to get for this car?

4. How do you guys rate this car? I know there were better versions (4.5L, 4.9L, N*) but still, is it an all around good car?

I'm looking forward to getting to work on the car to make it look and perform as great as it did back when it was new. It's a pretty exciting part of Cadillac history to own if you ask me so I'm eager to get going on it.....
 
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#33 ·
With the car off, you press the brake pedal 25 times, then with the key in the run position, engine off, crack open the bleeders at the master and electric supply pump one at a time to bleed. Have at least a qt of fluid handy. The pumps can be had rebuilt thru Allantesource.com or Tom Rohner in Los Angeles if needed. NO a Seville, Eldo and any other Cad had a completely different brake system, not adaptable.
 
#34 ·
With the car off, you press the brake pedal 25 times, then with the key in the run position, engine off, crack open the bleeders at the master and electric supply pump one at a time to bleed. Have at least a qt of fluid handy. The pumps can be had rebuilt thru Allantesource.com or Tom Rohner in Los Angeles if needed. NO a Seville, Eldo and any other Cad had a completely different brake system, not adaptable.
 
#35 ·
Sorry for the double post. I failed to mention that once you've pumped the pedal, you must hold it down before cracking the bleeder screw at the master. Did you read the tutorial on www.allantesource regarding diagnosing the brakes? I always used a clear hose submerged in a jar half filled with fluid and slipped over the bleeder screw to bleed my master and supply pump. Less chance of spraying fluid everywhere.
 
#37 ·
Today's events....

My friend and i got together and spent the whole day with the car. First thing we did was top off the trans fluid, and SeaFoam the car through the PCV. Drove the car back to my place to work on it. I experienced the same thing, poor shifting, and wouldn't drive very fast. We discovered the intake was frozen open and the pedal was stuck about halfway down. We corrected the frozen intake which now moves freely. The car now idles steadily for the most part around 800 RPM's and doesn't seem to stall very much at all. We then took to the soap and water and thoroughly cleaned the exterior of the car. The grime and dirt came off fairly easily to reveal the pearl paint which was in great shape. Took the car for another ride to try it out and we got better performance. We had it up to around 55 mph but the transmission still performed poorly. It has very rough downshifts, especially when going back to 1st when coming to a stop which can best be described as a slam. The car will also slam into gear when put into reverse or drive often stalling out the engine. We examined the trans fluid which we found to be brown for the most part, so it needs a trans service. We then took to the interior vacuuming out a vast majority of the 23 years worth of clutter and trash in the car. We got the driver's power seat to function once again and replaced some interior panels which were removed and never replaced. Then on to the brake system and discovered a leaking brake line going to the driver's front wheel. At about this time we decided to call it a day and head home.....

In short we need to do the following things to the car. Oil change, repair the brake leak, and transmission service. Hopefully the trans service straightens out the poor performance from the transmission. If the car needs a new trans that may pull the plug on the entire project since I'm not into dropping that kinda money into the car at this time. Everyone keep your fingers crossed it's something stupid like crappy fluid or a clogged filter.......

Here's the Allante all cleaned up and parked while we had a dinner break......

 
#38 ·
Above the throttle body is a series of vacuum hoses plugged into a small manifold. Remove this manifold and clean out the passages. Weak vacuum signals there can affect trans operation. The throttle plate bore should be cleaned with an old toothbrush and intake throttle body cleaner, beware though to clean only the primary (small) bore. Cleaning the larger bore can damage the TPS bolted to its shaft. If you follow these vacuum hoses they become hard metal lines that terminate at another vacuum hose rubber manifold at the rear of the engine just above the trans bell housing. This rubber manifold can deteriorate and cause issues with the trans. When doing the service use DEXTRON VI which is a synthetic blend. This transmission uses a regular vacuum modulator which can leak, so pull its hose off to verify no trans fluid within the hose. Also verify vacuum is present at this hose at the modulator. Excellent job so far!!
 
#40 ·
The trans service is just like any other trans service. Loosen pan. Remove bolts on one side to allow the pan to tilt to speed up draining. Remove the rest and replace the filter. Should have nothing in the pan but fluid and some silver mud. Do the service AFTER all the vacuum lines I mentioned are cleaned and vacuum is verified at the modulator.
 
#41 ·
Side questions.... How do you raise the soft top? I pulled it up manually but it won't go all the way to the windshield. It stops like 6 inches from the windshield and will go no further. Also the hard top won't lock into place in the middle where that loop is that goes into what resembles a hood latch. Tips?!
 
#42 ·
for the hard top pull the latch that says soft top/hard top release, i cant remember if its the bottom latch or top latch behind the driver seat.
that should open the "jaws" and allow the J hook to engage. you can then use the rocker switch to lower it.

on the soft top... are you engaging the FRONT hooks before the rear hook? the rear "bow" should stay locked until the front hooks are attached
 
#43 ·
here are instructions i posted for another member a while back

OffThaHorseCEO said:
to raise

- lower both windows or open both door (my windows dont roll yet)

- pull the switch to release the soft top hard cover

- slide the cover back then open

- pull the top up, until you get used to operating it, its best to do this with a helper, from both sides, and in a slow fluid motion. i usually grab the top by the latch handles, and by the rear bow and pull up and forward

- pull open the latches on the front of the soft top to lower the hooks

- manually engage the hooks, if you have a partner, close the latches together at the same time, if you dont have a partner, i go halfway with one, then go to the other side, go all the way with the other, then come back and finish the first side.

- AFTER the latches are engaged, go to the driver side and look right behind the driver door, right above the weatherstrip for the top. you should see a red latch, push the bottom of the soft top torward the front of the car a bit and release this latch but dont lower the back of the top yet

- close the soft top hard boot and slide forward, make sure it snaps in place

- inside the car, behind the drivers seat, on the underside of the boot is a rocker switch. iirc if you push it torwards the passenger side it lowers the pulldown assembly, torwards the drivers side it raises it. if its on the way up, you cant lower it until it gets to the top, if its on the way down you cant raise it again until it hits the bottom.

- You want this assembly raised. you may have to lower it all the way first and then raise it.

- So now, the front should be latched in, the back should be released, the boot cover closed securly and the pulldown mechanism should be in the up position using the rocker switch.

- grab the bottom of the soft top near the hook and gently lower it about halfway. you may TRY to gently lower it onto the pulldown assembly but it may not work. what i do is lower it about half way then firmly push it down, you could almost call it slamming it down. after that use your hand on the bottom center of the back glass area to keep pressure on the latch assembly. once it clicks your done!

If any of that doesnt work post back please



to LOWER the top if its raised completely, meaning pull down assembly is latched

- Pull the lever behind the drivers seat to release the top from the pulldown assembly

- grab the rear "bow" (bottom of the soft top) and pull up and torwards the front of the car

- AS YOU DO THIS, there is some fabric that MAY try to fold inward or downward. Again it helps to have a helper here. Try to make it fold outward instead. The two places are at the "C pillar" and at the very back of the "roof"

- Now pull the bootcover release latch

- slide the bootcover back and open

- push the rear bow torward the front of the car and engage the latch with the red handle, which will secure the rear bow in the up position. if you manipulated the folding material correctly, this should be VERY easy

- unlatch both the hooks from the front of the soft top

- slowly push the top up and back

- AGAIN THIS TIME watch how the fabric fold, there should be a HUGE piece of it that is supposed to fold outward, if it folds inward, your top will not lower all the way. it helps again to have a partner here until you get used to it

- now finish lowering it, my fabirc usually ends up covering the pulldown assembly so i move it off of there and make sure it all stuffed down correctly and lowered correctly.

- when your confident its as low as it can go, close the boot cover again.



again, if anything doesnt go as planned, post up here
im still not necessarily a pro at top raising/lowering so theres probably faster/easier ways but this is the way that works for me
 
#45 · (Edited)
oooo yea manual softtop

once you remove the hard top youll see 2 levers behind the driver seat, the bottom one will release the soft-top boot cover, it should pop up slightly, you can slide it back the up...

then manually lift the soft top using the instructions above

the rocker switch is on the underside of the rear shelf behind the driver seat. reach under there and feel around or have a peek under there. its purpose is to manually raise or lower the top pulldown assembly (the trunk latch looking thing) in case it accidentally improperly latches and lowers on its own.
 
#47 ·
Progress to report....

My friend and I spent a day with the Allanté on Sunday and got quite a bit done. We repaired a brake fluid and power steering leak, vacuum leaks, and replaced the PCV valve. We then removed the throttle body which was obscenely corroded with carbon and let it swim in parts cleaner. We also thoroughly scrubbed the plenum with a tooth brush and carb spray. While doing that I crawled under the car and did a trans fluid and filter change. All in all we've seen a vast improvement in the car's performance and shifting but it's still not 100%. Next on the list would be plugs and wires, followed by brakes all around, including a couple calipers in the front since the bleeders are seized preventing us from properly bleeding the system. It seems like the previous owners (before my girlfriend's dad) ran the car into the ground judging how bad the brakes were and how much the car seems to have lacked regular maintainence.....

For the moment the car is gonna have to sit for a bit since I've exhausted my funds for the project at the moment. I hope to be back at it before the snow begins to fall......
 
#48 ·
I would recommend you bleed the master and supply pump seperate from the calipers. They can be bled by simply turning on the key after you've pressed the brake pedal a minimum of 25 times to depressurize the accumulator. You were very lucky on the throttle body in the cleaner. Most times it damages the TPS switch. The book says to NOT clean nor spray the larger of the 2 bores because chemicals can damage the TPS. Use DELCO spark plugs for the newer 4.9 engine. Platinum and last 100,000 miles. Put a wrench on the bolts that hold the pulley on the water pump to make sure they're tight. Many came loose, damaging the pulley. Any electrical connections you unplug put dielectric grease on the pins, prior to plugging back in. Keeps electrical ghosts away!
 
#57 ·
Went by the Allante today and began to awaken it. Sure enough battery was very dead, and the two front tires are completely flat. I revived the battery successfully but the wheels gotta come off to bring the tires back. Fun stuff ahead......
 
#60 ·
The system is bled for the most part, the car needs a couple of calipers in the front since the bleeders have seized and I can't bleed the system properly. I'm waiting on that before I go any further with the brakes, however everything looks ok for the most part, I'm still working on getting it to run right after sitting all winter. I'm excited to be out there again.....
 
#61 ·
Update: Not a big one, but why not. I scored a brandy new alternator from an '89 Sedan deVille at the junkyard a few weeks ago. This alternator must've been just thrown in before the car was junked because it looks fresh outta the box. I swapped it into the Allante and it is a 99.9% perfect fit. The connections and mounting bolts are all the same, the only difference is the third mounting bolt (on the back) is in a different spot on the 4.5 DeVille but the alternator is secured perfectly and is working perfectly, the car is also running a lot smoother with the proper tension on the serpentine belt. The previous owner made a bracket and put a Frankenstein 100 amp alternator in there most likely out of a Chevy/GMC Silverado/Sierra which was putting out inadequate charge and way too much tension on the belt.

My next target is to get the fuel leak fixed, gas tank may have to come down for this one.....
 
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