I'm trying to bleed my brakes and get them working, but when i press the brake pedal, I hear a hissing sound. It' coming a top of the fuel tank(somewhere in that area.). where is the bleeder valve in this car?

That doesn't sound right, are you sure the hissing is from the brakes, is the brake fluid level going down and if so do you know where all the brake fluid is exiting the system.

 

Usual bleed points are at each wheel.  Have a look at the appropriate parts drawing. - https://skoda.7zap.com/en/cz/sk+105+20+30+35+36+garde/sko/1983-106/6/

 

ETA: It has been over 30 years since I had an Estelle 2 and the cars were under warranty and Dealership serviced so I don't remember the braking system.

Edited 28 December, 20232 yr by nta16
ETA:

Do these have a servo (it's been about 30 years since I worked on one, I can't even remember which end the fuel tank's in))? Sounds more like vacuum escaping to me. 

 

*Waits for someone to go full Sheldon Cooper on me because I said "Vacuum Escaping", which is a physical impossibility

Edited 28 December, 20232 yr by StevesTruck

Is there place to bleed them excluding the wheels? Also brake fluid doesn't decrease in level.

16 minutes ago, Nikiku said:

Is there place to bleed them excluding the wheels? Also brake fluid doesn't decrease in level.

@nta16 @StevesTruck and I are all thinking much the same thing; What you're describing sounds like a vacuum servo leak and will never be cured by bleeding the brakes.

1 hour ago, Paws4Thot said:

@nta16 @StevesTruck and I are all thinking much the same thing; What you're describing sounds like a vacuum servo leak and will never be cured by bleeding the brakes.

Oh ok, thanks for the info. Ill order new servo asap

Servo is punctured

Where Is the servo, could it not be repaired rather than replaced?

 

 

14 hours ago, StevesTruck said:

I can't even remember which end the fuel tank's in

I can't but imagine it behind the rear seats with the battery

tank is under the car in front of the gearbox, servo is in the front luggage compartment behind the bulkhead