1. Home
  2. Peugeot cars
  3. Problem replacing anti freeze 405 diesel

Problem replacing anti freeze 405 diesel

Did my usual routine on buying a second hand car with limited history. This includes replacing anti freeze.

Drained and refilled but would not take full amount of 7.8 litres (about 1 litre short - its the non turbo 1.9) I had the car jacked up on stands to try and overcome the air blockage problem with the heater being higher than the rad cap. Took the car on a test run and topped up with a very small amount of water when cold. Had the car on an extended run yesterday and I noticed a pool of water by the expansion tank this morning. Checked the level and it was ok.

However, I ran the engine for a few minutes - no heater. Guess there is air in the system and dumped some water when the water pump stopped.

I had a petrol (old version) 405 and I used to lever off the heater hoses at the bulkhead but the new (post 93) diesel heater hoses seem impossible to get at.

I have tried the Haynes manual "cut off bottom of plastic bottle and use as a header tank" method. Just leaks water/anti-freeze.

Any suggestions on how to top up the system gratefully received?

Reply to
confused
Loading thread data ...

I presume you have filled it with the bleed nipples open? Plus the one on the rad itself?

Reply to
Nigel

can't remember exactly where they are, never owned a 405 diesel, but worked on plenty and know there are a couple of bleed screws that need to be bled to rectify your problem, i think you will find one on the heater hose just where it goes through the bulkhead towards the heater matrix, and possibly another around the thermostat housing. you dont need to jack up the car in various positions to relieve the air, i have bled these many times quite easily without problem just using the bleed valves. hope this helps. steve.

Reply to
steve

Reply to
mindwipe

Thanks for replies

When I drained the system I released the bottom rad hose+hose to the thermostat+bottom bleed screw/+top bleed screw on rad. I also took off the plastic screw/hose to the expansion tank.

Refilling I left the top rad screw and plastic screw undone until mixture started to bleed.

Ran the engine to open the thermostat - takes for ever - then waited for system to cool down

Tried to locate this one - no joy. It would certainly help as the problem seems to be air trapped at the top end which means the heater matrix

Do you mean the engine thermostat?

.
Reply to
confused

Just a thank you to the various posters and to say that the problem was with the rad cap. It was lifting at under the 1.2 bar pressure and dumping anti-freeze.

A new cap from Halfords was £3.57. However the antifreeze is rather more expensive as I use the 5 year type and I will have to drain and top up to the 50% level required - I experience at least -10c and can be -25c on very extreme occasions.

Reply to
confused

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.