Alfa Romeo Forums banner

1 - 20 of 23 Posts

·
Registered
Joined
·
424 Posts
Discussion Starter #1
Hello,
I am restoring my 1969 USA Duetto and am faced with the dual brake booster system found in 1969. I have not yet gotten under the car but I am trying to find a schematic or an explanation for how the system works and what booster drives which brakes etc.... It is a dual circuit braking system with 2 boosters but 1 master cylinder (or 2 ?)..
I very much appreciate any explanation from any 1969 US braking afficionado.
Thanks

Roland
Paris France
 

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
Hi Roland,
The '69 US version Alfas have a dual circuit brake system that uses two boosters and one floor mounted dual circuit (or tandem) master cylinder. The top m/c in the attached pic is a standard ATE 22mm single circuit floor mounted cylinder. The bottom one is the one you have; an ATE 22mm floor mounted tandem cylinder for a lefthand drive car. The righthand drive tandem masters are different and not interchangable with LHD, but that's a discussion for another day.

The brake fluid reservoir is split into two chambers. Refering to the pic, the fluid from the front chamber goes to port #3 (the portion of the cylinder toward the rear of the car). When the brakes are applied, the fluid comes out port #4 and ends up in the side (just above the vacuum hose fitting) of the fender side booster after going thru the left side of the pressure switch cluster (more on that later). The fluid then exits the rear (the skinny end) of the booster and goes to a "T" fitting that's mounted on the lower right side of the firewall. Then it's on to the front calipers.

The rear chamber of the reservoir feeds the rear brakes thru ports #1 & #2 of the master and the firewall side booster.

The pressure switch cluster has two brake light switches activated by pressure, one in the front circuit and the other in the rear and third a switch for the brake failure warning light. The brake failure switch is a piston in a cylinder that is kept centered by equal pressure on both sides. If there's a pressure loss in one of the brake circuits, the piston moves in it's bore and provides a ground for the brake failure light.

Parts for this extremely rare m/c are available from www.alfastop.co.uk/english/index.html .

Hope this helps.
 

Attachments

·
Registered
Joined
·
424 Posts
Discussion Starter #3
Thanks more Qs..

Jim, many thanks.. great explanation... It is all clear to me know.... I had an old picture of the bottom of the car and noticed a second MC under the floor on the other side of the transmission. Is it a clutch MC ?
Also I noticed in back of the car a gizmo along the brake line.. It only has one input and one output so it isn't there to balance pressure between two lines.. What is it for ?
Here is the problem I have: When at a stop light and braking, my foot applied to the brake pedal would slowly go to the floor and I would lose the brakes.. So I would raise my foot and apply pressure again. It would be OK until my foot would again slowly go to the floor.. Is it bad seals in the brake MC ? If it is, Is it a simple dismantle, clean (changes seals they exist seperatly ?) change seals and put back together ?
Many thanks

Roland
Paris France
 

Attachments

·
Registered
Joined
·
424 Posts
Discussion Starter #4
2 nd photo

Jim,
here is a second pic with the rear brake line gizmo...

Roland
 

Attachments

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
Pretty clean looking underbody there Roland! What's the mileage? And how did a US spider end up in France?

The brake and clutch master cylinders are just as you labeled them in the pic; brake m/c on the inside of the chassis rail and the clutch on the outside.

The gizmo (technical term) is a brake fluid pressure regulator. It's supposed to limit the amount of pressure to the rear brakes to eliminate/reduce rear wheel lockup under hard braking. Don't know if it's too effective though. Used to run time trials with the added weight of the spare in the trunk to prevent unintended acceleration about the yaw axis while braking into a turn. After changing to an aftermarket adjustable regulator, I could run without the spare. It may just have been a bad regulator but the phycological advantage of an adjustable regulator was worth at least a second a lap!

If the brake pedal of any vehicle slowly sinks under foot pressure and there are no hydraulic leaks, then the primary seals in the master are kaput (a 'G' rated technical term). The seal kit available from Alfastop has the 5 piston seals, bellows and the sealing washer for the front brake piston limit bolt. Their full kit, manufactured by ATE, includes the pistons and check valves as well as all the seals. Light rust in the cylinder bore can be honed out but any pitting or scoring will require a re-sleeve.

PS - maybe it's the photo or my glasses are crooked but the track rod looks bent.
 

·
Registered
Joined
·
424 Posts
Discussion Starter #6
Con't

Jim,
Thanks.. i'll look into dismantling the MC to find out the pb.

To answer your initial question, this Duetto was imported by a friend of mine (women) from San Francisco (car from Hawai) into france but left it in a garage for 3 years with no particular care... My friend eventually sold it to me. A very sad thing happened a few weeks later as I was going to have the car's brakes redone (poor braking after 3 yrs in storage)... We were caught in a 5 car pile up on a french highway... We were the last car in line (no rear damage). I could not compete with the ABS brakes of modern cars and were not prudent enough (lesson to be learned) with distances between cars in heavy traffic.... Well here are 3 pics to describe the damage... Insurance does not cover repairs so I am trying to find good but economical ways to reapir. I have found 2 duetto shells (for the front body parts - new parts is too expensive).... The rest I will by from distibutors of try to find good condition old parts... Everything if pretty available here (for a price !) .. a few parts I am having trouble with is the water pump which seems to be specific to spica injected (therefore US) versions. I'll try to get it form the states. Other than that the project has not yet started as I am still negotiating for the body shell. I have 2 relatively inexpensive body shps interested. One (already done a great job on a friends coda tronca) will take parts from the duetto shell, the other has an original engine bay body assembly which he wishes to use. Body panels he said he can save or make from scratch (incl rebending bumbers etc... severe metal working capability ??).... Any thoughts ?
Thanks

Roland
 

Attachments

·
Trained (ex)Professional, , 1953-2018 RIP,
Joined
·
16,232 Posts
OUCH!! Brings a tear to my eye. Even the right front floor looks damaged. You might want to try Richard Banks at www.alfaholics.com in England. He has a bunch of used stuff as well as the Spica version water pump.
 

·
Registered
Joined
·
4,450 Posts
Hey Roland:

Sorry about your luck. I had a similar accident last fall. Your damage looks more significant than mine. Sheet metal wise, looks like you just need the hood, upper and lower nose, and the passenger side fender. From the looks of it there is no way those will be straightened. No doubt you will need that upper radiator support with the hood hinges and under hood valence. A good nose clip will have it all. I am surprised it got to your pass. front wheel. Looks like that center steering rod is bent and your wheels splayed out. Maybe a little frame damage to that pass. wheel assembly to be pulled. Bottom other than that looks pretty good. I think your radiator is pretty common. I see it has the curved neck on the top. I know early Bosch Spiders and Spica Spiders had those as well. www.international-auto.com has new water pumps for spica injected cars. Looks like it was a beautiful car and well taken care of. She will be as good as new when the shop gets done.

Best of Luck,
John M
 

·
Registered
Joined
·
424 Posts
Discussion Starter #13
69 resto

Ossodisepia,
First of all I saw your pics posted online... Beautifull work !!
I am way behind you and will probably not go as far due to budget, tooling and timing restrictions but my restoration will be a nuts and bolt as your is.
Where am I ? Well, I have dismantled the whole car (engine and trans out 2 weeks ago) except the suspension. my next project is to build an inexpensive dolly so I can remove the suspension. By the way how heavy is the empty body ? Can 1, 2 or + people lift it ?
I have a few pics posted (see link below) but will be redoing and extending the picture selection in the next week to make it more interesting.
I additionnaly have hundreds of pictures of my car at every step of the dismantling. I have lots of disk space and bought a 4M pixel digicamera this year so I shoot anything I dismantle . I assume this will be the best tool to hep me remember how to put things back together when the time comes. If you need anything please just let me know and I will send you pics of it.

Quick question. i am asking myself how to recondition the suspension. Do I change all the bushings ? How do I clean up the parts and what are the steps/products to refinish them with ?

Glad to be of any help. You can contact me directly if you wish at [email protected]

Roland
 

·
--ADMINISTRATOR--chiuso per ferie
Joined
·
12,313 Posts
Hi Roland,

When I dismantled my car, I took as many pictures as I could. I did not have a digital camera back then. The digital camera is the way to go, because you can check your pics on the spot. In some cases, I didn't take enough pictures or missed some things altogether. The digital camera should solve this problem for you.

I'm not sure how much the chassis weighs when it's stripped down. I think three people can do it, maybe two very strong ones. If you build a dolly like mine, you can do it all by yourself. I'll be happy to post a picture. My dolly is stout enough to hold 2800 lbs, about 1275 kilos. If you look closely, you can see that each wheel of the dolly is positioned directly below each of the jack points. This ensures that the weight is transfered directly to the wheels. The wooden frame is there only to hold the wheels togther.

As for the suspension, now is the time to redo everything. If you rebuild it now, it will be a little less expensive because all of the stuff is off the car. I had all of my mine powder coated. It was cheap, about $600. The place that I used bakes everything at 400 degrees F to remove grease and oil. Then, the parts are media blasted before the powder coat is applied. I could not have had these pieces painted for that cheap. $600 is a lot of money to spend, but I felt it was cost effective to have the powder coating done. Besides, it really looks great.

Thanks for your offer for help and thanks for posting the pictures of your doors guts. You have resolved my issue, and I thank you for that. Let me know what I can help you with. I'll scan the picture of my dolly tonite and get it to you.

Brian
 

·
Registered
Joined
·
424 Posts
Discussion Starter #15
Bushings

Brian,
quick question. You changed all your bushings I assume. Did you go rubber or poly (I asusme rubber). Any issues fitting them without speialized tools ?
Where did you get buy them ?
Thanks

Roland
 

·
--ADMINISTRATOR--chiuso per ferie
Joined
·
12,313 Posts
Hi Roland,

Yes, I replaced all of the bushings. Don't buy any or the aftermarket crap. I had a heck of a time with the aftermarket trailing arm bushings. The outside diameters are inconsistant, and they may not fit. The bushings need to press in. The ones I bought from International Auto here in the states were crap. I could push them in with my fingers. Get yours from Alfa Romeo.

As for pressing them out, I have a 20 ton press, it makes it real easy. Most of them you can press out using a long bolt and some bearing races and sockets. Leave the trailing arm bushings to an Alfa mechanic. They will need to be cut out.
 

·
Registered
Joined
·
424 Posts
Discussion Starter #17
Bushings

Thanks Brian for the info.. i am surprised that IAP stuff seems below par. You mention getting stuff from Alfa.. well i don't think Alfa carries stuff for the 105 line. or am I wrong ? I got most of my info from french aftermarket distributors (well they have aftermarket and non-aftermarket stuff), alfa club members etc.... Everyone gets stuff from a few distributors in France who get most of their stuff from italy and other places... but I assume IAP does too.
I can surely find someone with a press in the area to get that stuff out and then in again.

When do you plan on being finished ? Do the photos online pretty much show where you are today ? i'm interested to guage your advancement because I would like to have this all back together for next summer.
For your curiosity I met this guy in France who did a frame up (1971 kamm tail) in a year.... although this is in French you might like to see the pics.
See: http://www.alfaclassicclub.com/alfaclassicclub.htm
Click "Virus Alfa" (at the top menu)
Click "Gildan 1750 spider" (on the left menu)

Roland
 

·
--ADMINISTRATOR--chiuso per ferie
Joined
·
12,313 Posts
Cool, I'll check out the restoration. I would like to have mine done by next year as well, but it may not happen. Everything takes time. It seems that each thing I need to do takes a half day. It tooka a half day to get my dash reassembled. I had to buff up the chrome on the instruments and them put everything back to gether on a new dash cap and knee pads.

You'll be surprised at how long it takes to do things. What you see in the pictures took about a week. The suspension and wire harness are easy. Cleaning and painting take up loads of time. If you're not married or have kids, you can devote all of your waking hours to the restoration and get it done in a reasonable amount of time.

What may take time is the body shop. My car has been thru three shops. The third was the charm.
 

Attachments

·
Registered
Joined
·
424 Posts
Discussion Starter #19
Nice !

Brian your dash is a beauty !!! I hope to get mine looking like that too. I want to make sure that the interior is aesthetically very clean and pristine. The insides on my dial guages has dust and stuff even some paint on needles is crumbling... Will look at dismantling and cleaning (surely will take time !). The chrome housing around the oil, fuel and temp guages is not perfect. They are plastic if I recall so buffing won't do them good. What were yours made of ? The front edge of the guages are also worn a bit (no chrome).
Probably need to buy new ones ? Or have them refinished (possible ?).
 

Attachments

·
--ADMINISTRATOR--chiuso per ferie
Joined
·
12,313 Posts
Are you going to buy a new dash cap and knee pads? The three angled chrome pieces around the oil, water and fuel guages are plastic. I got some from a 66/67 Duetto. They are made of pot metal. I had those refurbished and rechromed. They look much better than the plastic ones. I believe I've seen new plastic ones in recent years. The trim rings around the guages, I think are chromed brass pieces. I scavenged up some guages that were in better shape than mine. All I had to do was shine them up.

Since you are in France, you should consider going to one of the big Mostre Scambios in Italy in the spring. Save up your money and buy everything you need there.

Do you have an ftp site that can handle about 100 MB at your disposal? If so, I would like to ftp something to you.
 
1 - 20 of 23 Posts
Top