1999 Honda Civic Owner's Manual - Page 181

Transmission Fluid, Brake and Clutch Fluid 5-speed Manual Transmission FILLER BOLT If Honda MTF is not available, you may use an API service SG, SH or SJ grade motor oil with a viscosity of SAE 10W-30 or 10W-40 as a temporary replacement. An SG grade is preferred, but an SH or SJ grade may be used if SG is not available. However, motor oil does not contain the proper additives and continued use can cause stiffer shifting. Replace as soon as convenient. The transmission should be drained and refilled with new fluid according to the time and distance recommendations in the maintenance schedule. Brake and Clutch Fluid Check the fluid level in the reservoirs monthly. There are up to two reservoirs, depending on the model. They are: Brake fluid reservoir (all models) Clutch fluid reservoir (manual transmission only) The brake fluid should be replaced according to the time and distance recommendations in the maintenance schedule. Correct level Check the fluid level with the transmission at normal operating temperature and the car sitting on level ground. Remove the transmission filler bolt and carefully feel inside the bolt hole with your finger. The fluid level should be up to the edge of the bolt hole. If it is not, add Genuine Honda Manual Transmission Fluid (MTF) until it starts to run out of the hole. Reinstall the filler bolt and tighten it securely. Maintenance