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Tech QuestionsJanuary 2004 Tech Q & A

Answers by Technical Editor Rex Chalmers

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January Topics:

Berlina Brake Bleeding | Street Snap for GTV/6 | Super Gear Box Rebuild| Noisy Graduate
Engine Break In | Milano Self Leveling Suspension | Alfetta Oil Pressure | Berlina LSD
GTV Gas Gauge Problem | Stuck Brake Pistons | Rear Motor Mount Replacement

Berlina Brake Bleeding: question by Mitch Wollberg | 1969 Berlina

I'm wondering what's the best way to bleed the brakes on the 69 dual circuit with floor mounted pedals. No matter how many times I've tried I still have some air in the system.

I've got a resleeved master cylinder, replaced the rubber hoses and the rear brake compensator, and removed the non-functioning boosters. The brakes work but there's still a difference of a 1/2" in pedal height between the first and second pump of the brakes.
Answer : I use a Snap-On pressure bleeder. It’s a plastic tank with a hand pump that builds pressure in the tank to supply the brake hydraulic system with pressurized brake fluid. Believe it or not, Snap-On sells an adapter that fits the Alfa reservoir to facilitate connection of the bleeder hose to the braking system. You just pump up the pressure, open the bleeder, stroke the brake pedal a few times and then watch the fluid coming out of the caliper. When it is free of air bubbles, close the bleeder and move on. I have tried most patterns of bleeding at the calipers and have found that the traditional RR, LR, RF, LF pattern of bleeding works perfectly well in most cases. Some techs I know prefer bleeding both rears simultaneously and then both front simultaneously, while others bleed the right side simultaneously and the left.

If you don’t have a pressure bleeder, I like the “pressure surge” method of bleeding. Make sure your reservoir is full, attach a clear hose to the RR bleeder and then have your assistant pump up the brake pedal and hold the pressure on the pedal. Now open the bleeder, when the pedal hits the floor, have your assistant hold the pedal down. Now close the bleeder. Repeat the procedure until all air bubbles have disappeared from the fluid. Repeat the procedure at each caliper following whichever pattern you deem best.

The condition you describe is fairly common in this system and I have seen this condition in vehicles where the hydraulic system is completely free of air. If, when you bleed the brakes, you are constantly getting air out of the bleeders, you most likely have a problem with either the master or one of the boosters allowing air into the system. You don’t mention if the pedal is “spongy” and pumps up or if the pedal is hard and just moves up the second time it is depressed. If it is not “spongy” and you are just getting a change in pedal height, chances are that the boosters and master are OK. It is, however, possible that a problem with the pistons and seals of the boosters or the master could still be the culprits. If you are not getting air in the fluid coming out of the bleeders, the most common cause of this problem is found in the brake calipers. If your brake calipers are original, they are 34 years old! Often calipers of this age are in the beginning or middle stages of seizing and, in this condition, the pistons will retract more than their design parameters would like when hydraulic pressure is released, because the corrosion is actually holding them in place. When you push on the brake pedal you apply hydraulic pressure to the pistons. Corroded pistons, bores, or bad seals will not allow the pistons to move as freely as they normally would. This abnormal movement could be what you are feeling when you have to depress the pedal a second time to achieve nominal pedal height. Also, inspect your brake hoses. If they are fatigued, they may be stretching under hydraulic pressure, although the symptom would be a soft pedal. If the hoses were deteriorating internally the symptom would be a hard pedal and even sticking on of the brakes as they heat up. If your brake discs are worn or warped, the pads may not be seating correctly. This condition can also cause the brake pedal problem you are describing. If the discs are warped they can actually be moving the pistons back into the calipers so that the brake pedal will have to travel further to displace enough fluid to move the brake pads into contact with the brake discs. This condition would normally be accompanied by a “pulsating” brake pedal. There are a number of variables to deal with here and it is your brakes we are talking about, so you may want to consider taking your baby to your local friendly Alfa tech, and let him have a go at your problem.

"Street Snap" for GTV/6 : question by Bob Rocco | 1984 GTV/6

I pulled the heads on my '84 GTV-6 due to high oil consumption. The guides were perfect, professionally verified. The aftermarket seals were bad. We're putting in S cams, but I'm told 10:1 pistons would be much better than the cams alone. Downstream there's a Ricambi cat and Stebro center; stock tail. Will the computer handle all this? What about a 2.8 conversiion? I just want some extra street snap.
Answer : If you were going to go the 2.8 route, I would seriously consider finding a 3.0 and installing that motor. In stock form, a 3.0 will provide about 190 HP. S cams and 10:1 pistons in a 2.5 might get you to 175 HP or so, but you still will not have anywhere near the torque of the 3.0. It would cost more to add S cams, 10:1 pistons, and go through the engine than it would to install a stock re-furbished 3.0.

That being said, of course, 10:1 pistons will give a nice HP increase and better throttle response. It would definitely give that “extra street snap” you were asking about. When used in combination with S cams, you will get a very nice increase in performance. Although the computer will handle the modifications you propose, you will be wishing for a modified ECU to raise the rev limiter and provide a tad more fuel mixture.

Now if you took a 3.0 added 10:1 pistons, S cams, big valves, porting, matched intake runners, and modified the ECU, you would have something on the order of 250+ HP. Wouldn’t that be fun?

Super Gearbox Rebuild : question by Scott Fowler | 1967 Giulia Super

I am upgrading the engine in my '67 Super from the stock 1600 to a 1750 but keeping the original gearbox using the 1750 clutch assembly and throw out bearing adapter. I was wondering when rebuilding the gearbox if you recommend converting the synchros to the later style, lightening the gears or both? Also are there any other suggestions to upgrade an older style gearbox?

Answer : Yes, absolutely change to moly synchros. It is important to change all the detents and limit straps for each gear when making the change. I believe Centerline, in Boulder, CO, actually sells a kit containing all of the parts necessary to make the change. When dealing with a 35 year old gearbox, it is a good idea to re-bush all the gears, carefully clean and inspect all the bearings, measure the shift forks for wear, replace all the shift fork bolts, and any selector rings that are worn. Although it is not required, I would suggest replacing all the selector rings to the later style selector, they will give a more positive feel to the gear change and provide longer synchro life. Be sure to check the shift rod pawls, detent balls and springs. You might consider installing a later style, needle bearing 5th gear. Good used 5th gears are a fairly common piece as they rarely wear out.

As far as lightening the gears is concerned, that is a topic that has been the subject of much discussion and debate for many years in Alfa circles. Personally, I am skeptical as to any quantifiable benefits. In theory the benefits would include less drag on the engine, therefore more HP at the rear wheels. Also, less reciprocating mass should translate to longer synchro life …in theory. It’s a fairly expensive procedure, I’d think long and hard before laying down the cash.

Noisy Graduate : question by Don Malcom | 1990 Spider Graduate

I just bought this car one owner 53000 miles and the engine seems to be noisy is this normal .. my first Alpha. It appears to be in the valve train i think.. it runs goods ,but then again i dont have a good referance.. it has a header on it stock exhaust.. any after market muffler out there.
Answer : First and foremost, it’s ALFA.

The last series Spiders seem to have a penchant for this particular noise. First check the valve clearances, cam timing, the condition of the cam followers and the camshaft lobes. Once you have verified the condition of these items and repaired or adjusted where necessary, start it up and see if the noise has dissipated. If it persists, chances are that you have a case of worn valve guides. I know it seems like low mileage for worn valve guides, but it happens to late model Spiders all too often.

Engine Break-In : question by Dan Schaefer | 1972 GTV 2000

What is the proper way to brake in a rebuilt engine? What oil should I start with, where should I keep my revs at for the first 500 miles...?
Answer : The following is the break in procedure that I have been massaging over the last 30 years of building engines. It’s worked for me and for my customers.

Engine Break In Procedures:

When driving the car with a new engine it is advisable to never drive the car for less than 20 min. Driving the car for this length of time will allow the engine to come to full operating temperature and facilitate proper mating of the piston rings, bearings and other rotating components.

Following first start and full 10 minute driving warm up, accelerate the engine in 3rd gear to 4,500 rpm and allow the engine to decelerate to around 2500 rpm. Repeat this procedure 10 times in succession. Performing this procedure will go a long way towards breaking in the piston rings.

When highway driving, never cruise in the same RPM range for more than 10 minutes. Use the engine to do some braking by lifting of the accelerator with the car in gear and allowing the engine to decelerate under load which will help the piston rings to seat .

DO NOT idle “warm up” the engine for more than three minutes. Piston rings are at their least efficient when they are cold and idling. This fact , added to the rich condition your fuel system dictates when it is cold, is good reason not to warm up too long. Do not use full throttle until engine has over 1000 Miles running time. Do not run engine over 3500 RPM until it is fully warmed up. Do not run engine over 5,000 RPM for the first 500 miles.

Do not exceed 5,500 RPM for the next 1000 miles.

Change oil and filter, torque cylinder head, and check valve adjustment at 500 to 750 miles.

Change engine oil and filter every 3000 miles or 3 months, whichever comes first, after initial 500 miles Break in period. If you want to do more frequent oil changes, do it. Nothing helps your seals, gaskets, rings, bearings, valve guides, and head O-rings to provide a long service life more than fresh oil.

Check oil and coolant levels frequently. Always check these levels on a cold engine before starting.

Milano Self-Leveling Suspension : question by David Martin | 1988 Milano Platinum

I just bought my second milano, an 88 Platinum with self leveling suspension. It has a hard ride and most people tell me to convert it to convetional shock system, but I would like to keep it. Should i keep it or convert? If I keep it how do I fix the ride problem? If I convert it do all standard Milanos have a raised back end ?
Answer : If it were my Milano, I would convert to a standard shock/spring combination. You don’t mention if the system is functioning correctly. I suspect that it is not. If it were, the ride would not be “hard” as you describe. You could diagnose the cause of your concern, however I would suspect that the cost of repair would probably exceed the expense of converting to the standard shock/spring combination. Before you decide, I would be a good idea to find out if repair parts are available.

Milano ride heights did vary somewhat over the years, with later cars having less of a riased rear. Several suppliers sell sport springs which will lower the car slightly without sacrificing too much ground clearance.

Alfetta Oil Pressure : question by John Harriott | 1975 Alfetta

I recently purchased the car and noticed the oil pressure seemed low. I attached a mechanical pressure gage. When the engine is fully warmed up, the pressure is about 30psi at 3000 rpm. It does move higher, maybe to 50 psi at 5000 rpm. At idle, it is very low. Is this a problem?
I also own a spider, the gage in it (not mechanical) reads about 55 psi at 3000 rpm.

Answer : If we assume that the mechanical gage you used is reading correctly, your oil pressure is out of specification. Hot idle readings are, typically, very low, the factory specification for idle is 7-14 PSI. Max hot oil pressure at anything over 3000 to 4000 rpm is 65-70 PSI. The minimum max hot oil pressure is 50 PSI. Both your engines use the same oil pump with the same pressure relief settings. I would check your spider with the mechanical gage and compare the readings. 30 PSI at 3000 seems a bit low. I would drain the oil and check the magnetic drain plug to see if there is any bearing material on the plug. Assuming that your engine is mechanically sound, and not getting ready to ventilate itself, my best guess is that you have a crank plug or plugs that are no longer in the crank, but are lying in the bottom of the oil pan. It is possible that you have a clogged CHEAP oil filter with no, or a mal-functioning by-pass, or a pressure relief valve that is mal functioning in the oil pump. You could try changing the oil filter before you take the pan off. The '75 vintage Alfa 2.0 Liter engine is famous for spitting out crank plugs. Loss of even one crank plug will cause an overall loss in oil pressure. If you pull the oil pan and inspect the crank, I suspect that you will find at least one crank plug not in it’s proper hole in the crank. If that is the case, a new crank plug can be easily installed and you problem should be solved, assuming that no damage had been done to the engine’s bearings or bushings by the lower than normal oil pressure.

Berlina Limited Slips : question by Gerard Bader | 1975 Berlina

I read your message about the 1978 Spider concerning the limited slip differential. May I take it that the LSD protrusion also goes for my Berlina ?

Some people are convinced that all Berlinas were equipped with LSD, I however am not. This because of a 1974 2000 Berlina sales brochure (in Dutch) that I have, wherein is stated that LSD is an option.

Could you be the judge in this matter ?
Answer : I would be happy to act as supreme arbiter in this matter. All 2.0 Liter 115 chassis Alfas, Berlinas, GTVs, and Spiders, imported into the USA were equipped with LSD. I can’t speak for all the countries on the planet, but I believe you are correct that in most other markets, LSD was an option.

GTV Gas Gauge Problem : question by Garrett Budwine | 1969 GTV 1750

My fuel gauge indicates from empty (when full) to full (with about 1/4 tank) and the low fuel light does not come on. I have tried reversing the wires at the sending unit, but then the gauge does not respond at all and the low fuel light stays on all the time. Any ideas or suggestions?
Answer : Sure, with the ignition on, ground one of the fuel tank sending unit wires. Either the fuel light should come on, or the gage should go to full. Next, ground the other fuel tank sending unit wire. Now whichever indicator didn’t occur when you grounded the first wire should occur when you ground the second. This test will prove out the wiring to the gauge and the overall functioning of the gauge. If both actions occur, i.e. the gage goes to full when one wire is grounded and the low fuel light comes on when the other wire is grounded, you can be fairly certain that there is no fault in the gauge or the wiring to the gauge. About 90% of the time, the fault lies in the sending unit. From the symptoms you describe, it sounds like a sending unit to me. If the test I describe points elsewhere, you may want to seek professional help with gauge repair.

Stuck Caliper Pistons : question by George Emmett | 1973 Spider

How do I get the pistons out of the calipers to rebuild them air does not seem to work and when they are split it gets even harder. The car only has 10 thousand miles on it and I want to clean them up and re seal them. I am used to applying low pressure air to the bleeder and having them pop out, so far no luck.
Answer : Let’s think, 10,000 miles and 30 YEARS LATER the brake caliper pistons are stuck in their bores, I’ll wager that the pistons are seized in their bores with corrosion. If you can’t budge the pistons with air pressure, you have a problem. You can try soaking them in WD-40, then judicious application of heat with a propane torch. Failing that, make up an adapter that will allow you to attach a grease gun to the threaded bleeder bore in the caliper. I have never met a caliper that I couldn’t get the piston out of with the old grease gun. The grease gun will produce much more pressure than any shop air compressor.

In this case, I would recommend getting on the horn to one of the independent Alfa parts suppliers, and ordering a set of re-manufactured calipers unless you have some emotional attachment to the original calipers. Chances are that after 30 years and what I would suspect is some very contaminated brake fluid, I am fairly certain that the caliper pistons are pretty well seized up in their bores. Even if you got the pistons out of their bores, they would probably not be useable and need to be replaced or re-sleeved.

Motor Mount Replacement : question by Joe Pagano | 1986 Spider

I am looking to replace my rear mount. How do you get the old press fit mount out of the transmission? I am not dropping the trans it is still in the car. Can you remove the old mount without removing the transmission?
Answer : Yes you can. First remove the transmission mounting plate from the chassis and the transmission. I like to take the nuts off the center bearing support in order to not damage the support. An added bonus is that the back of the transmission gets lower. If you need more room to get at the mount, disconnect the drive shaft at the differential and jack up the front of the engine. Now, take out your propane torch and heat the rear transmission mount housing until the rubber in the mount starts to smoke. Now, quickly, take a 6” or 8” long punch and carefully tap the mount out of its housing. Be careful not to deform the steel shell of the mount, as doing so will make it very difficult to remove the mount. It will probably cock in the housing; so at that point tap the mount on the opposite side to avoid jamming the mount in the housing. If you have the housing hot enough and haven’t jammed the mount into the housing, the mount should now be a hot, steaming, smelly, used unit laying on the shop floor. Don’t pick it up without some protection, as it will be hot enough to burn your hands. Next, I like to use a “brush research” ball hone to clean up the inside of the housing. After that, I clean the inside of the housing out with brake clean and compressed air. Prep the new mount by cleaning off any stickers, adhesive or dirt with brake clean or lacquer thinner. Do not freeze the mount before trying to install it, I know it is tempting, but it often doesn’t work. Now heat the housing with the propane torch for about 5 minutes. If you got the housing hot enough, slight tapping with a small hammer should install the mount with very little resistance. If it doesn’t want to install, don’t force it. Remove the mount and once again go through the preparation procedure and re-install the mount. Sight the mount from the back side and make sure that it is centered in the housing. I have been using this procedure for years, if you prep the mount and housing correctly and are careful to install the mount without cocking it in the housing, you should have little trouble renewing the mount.

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